From f1043734438c8518a302f698d9ae6583a75f0c14 Mon Sep 17 00:00:00 2001
From: cashmere <cashmere@autistici.org>
Date: Sun, 16 Aug 2026 06:16:56 +0200
Subject: feat: add transitions, track mixing, and voiceover controls

---
 apps/web/src/actions/use-editor-actions.ts         |  41 ++-
 apps/web/src/commands/timeline/track/index.ts      |   1 +
 .../commands/timeline/track/update-track-volume.ts |  38 +++
 .../src/components/editor/panels/assets/index.tsx  |  12 +-
 .../editor/panels/assets/views/transitions.tsx     | 258 +++++++++++++++++
 .../components/track-audio-properties.tsx          | 158 ++++++++++
 .../components/editor/panels/properties/index.tsx  |  21 +-
 .../editor/panels/properties/registry.tsx          |  38 ++-
 .../panels/properties/stores/properties-store.ts   |  44 +--
 apps/web/src/components/ui/slider.tsx              |  63 ++--
 apps/web/src/core/managers/audio-manager.ts        |   1 +
 apps/web/src/core/managers/timeline-manager.ts     |  15 +-
 apps/web/src/media/audio.ts                        |  42 ++-
 apps/web/src/params/registry.ts                    |  77 +++--
 .../web/src/rendering/__tests__/transition.test.ts | 166 +++++++++++
 apps/web/src/rendering/transition.ts               | 194 +++++++++++++
 .../__tests__/scene-builder-transition.test.ts     |  99 +++++++
 apps/web/src/services/renderer/nodes/text-node.ts  |   2 +
 .../web/src/services/renderer/nodes/visual-node.ts |   3 +
 apps/web/src/services/renderer/resolve.ts          |  67 +++--
 apps/web/src/services/renderer/scene-builder.ts    |  46 ++-
 .../web/src/timeline/__tests__/audio-state.test.ts |  65 +++++
 apps/web/src/timeline/audio-state.ts               |  20 +-
 .../__tests__/drop-target-transition.test.ts       | 221 ++++++++++++++
 apps/web/src/timeline/components/drop-target.ts    |  90 +++++-
 apps/web/src/timeline/components/index.tsx         | 140 ++++++---
 .../src/timeline/components/timeline-toolbar.tsx   |  27 +-
 .../drag-drop-controller-transition.test.ts        | 190 ++++++++++++
 .../timeline/controllers/drag-drop-controller.ts   |  71 ++++-
 apps/web/src/timeline/defaults.ts                  |   9 +
 apps/web/src/timeline/drag.ts                      |  92 +++---
 .../src/timeline/hooks/use-timeline-drag-drop.ts   |   1 +
 apps/web/src/timeline/placement/track-factory.ts   |   2 +
 apps/web/src/timeline/scenes.ts                    | 229 +++++++--------
 apps/web/src/timeline/types.ts                     |  10 +
 apps/web/src/voiceover/__tests__/devices.test.ts   |  72 +++++
 .../src/voiceover/__tests__/enhancements.test.ts   | 133 +++++++++
 apps/web/src/voiceover/devices.ts                  |  93 ++++++
 apps/web/src/voiceover/enhancements.ts             | 321 +++++++++++++++++++++
 apps/web/src/voiceover/live-waveform.tsx           | 171 +++++++++++
 apps/web/src/voiceover/recorder.ts                 |  40 ++-
 apps/web/src/voiceover/voiceover-popover.tsx       | 276 ++++++++++++++++++
 apps/web/src/voiceover/voiceover-store.ts          |  57 +++-
 43 files changed, 3355 insertions(+), 361 deletions(-)
 create mode 100644 apps/web/src/commands/timeline/track/update-track-volume.ts
 create mode 100644 apps/web/src/components/editor/panels/assets/views/transitions.tsx
 create mode 100644 apps/web/src/components/editor/panels/properties/components/track-audio-properties.tsx
 create mode 100644 apps/web/src/rendering/__tests__/transition.test.ts
 create mode 100644 apps/web/src/rendering/transition.ts
 create mode 100644 apps/web/src/services/renderer/__tests__/scene-builder-transition.test.ts
 create mode 100644 apps/web/src/timeline/__tests__/audio-state.test.ts
 create mode 100644 apps/web/src/timeline/components/__tests__/drop-target-transition.test.ts
 create mode 100644 apps/web/src/timeline/controllers/__tests__/drag-drop-controller-transition.test.ts
 create mode 100644 apps/web/src/voiceover/__tests__/devices.test.ts
 create mode 100644 apps/web/src/voiceover/__tests__/enhancements.test.ts
 create mode 100644 apps/web/src/voiceover/devices.ts
 create mode 100644 apps/web/src/voiceover/enhancements.ts
 create mode 100644 apps/web/src/voiceover/live-waveform.tsx
 create mode 100644 apps/web/src/voiceover/voiceover-popover.tsx

(limited to 'apps/web')

diff --git a/apps/web/src/actions/use-editor-actions.ts b/apps/web/src/actions/use-editor-actions.ts
index ca16e989..b165d5ef 100644
--- a/apps/web/src/actions/use-editor-actions.ts
+++ b/apps/web/src/actions/use-editor-actions.ts
@@ -44,7 +44,11 @@ import {
 	stopVoiceOverRecording,
 } from "@/voiceover/recorder";
 import type { VoiceOverRecordingResult } from "@/voiceover/recorder";
-import { useVoiceOverStore } from "@/voiceover/voiceover-store";
+import {
+	useVoiceOverPreferencesStore,
+	useVoiceOverStore,
+} from "@/voiceover/voiceover-store";
+import { applyVoiceOverEnhancementsToBlob } from "@/voiceover/enhancements";
 
 const FREEZE_DURATION_SECONDS = 3;
 
@@ -651,7 +655,9 @@ export function useEditorActions() {
 
 			if (voiceOverState.status === "idle") {
 				try {
-					await startVoiceOverRecording();
+					await startVoiceOverRecording({
+						deviceId: useVoiceOverPreferencesStore.getState().selectedDeviceId,
+					});
 				} catch (error) {
 					toast.error(getVoiceOverErrorMessage({ error }));
 					return;
@@ -662,11 +668,16 @@ export function useEditorActions() {
 				return;
 			}
 
-			useVoiceOverStore.getState().stopRecording();
+			if (voiceOverState.status === "processing") {
+				return;
+			}
+
+			useVoiceOverStore.getState().processRecording();
 
 			const activeProject = editor.project.getActive();
 			if (!activeProject) {
 				cancelVoiceOverRecording();
+				useVoiceOverStore.getState().stopRecording();
 				return;
 			}
 
@@ -675,18 +686,35 @@ export function useEditorActions() {
 				recording = await stopVoiceOverRecording();
 			} catch (error) {
 				toast.error(getVoiceOverErrorMessage({ error }));
+				useVoiceOverStore.getState().stopRecording();
 				return;
 			}
 
 			if (recording.blob.size === 0) {
 				toast.error("Voice-over recording is empty");
+				useVoiceOverStore.getState().stopRecording();
+				return;
+			}
+
+			const enhancements = useVoiceOverPreferencesStore.getState().enhancements;
+			let assetBlob = recording.blob;
+			let assetMimeType = recording.mimeType;
+			try {
+				assetBlob = await applyVoiceOverEnhancementsToBlob({
+					blob: recording.blob,
+					settings: enhancements,
+				});
+				assetMimeType = assetBlob.type || recording.mimeType;
+			} catch (error) {
+				toast.error(getVoiceOverErrorMessage({ error }));
+				useVoiceOverStore.getState().stopRecording();
 				return;
 			}
 
 			const file = new File(
-				[recording.blob],
-				`voice-over.${getFileExtensionForMimeType({ mimeType: recording.mimeType })}`,
-				{ type: recording.mimeType },
+				[assetBlob],
+				`voice-over.${getFileExtensionForMimeType({ mimeType: assetMimeType })}`,
+				{ type: assetMimeType },
 			);
 			const addMediaCommand = new AddMediaAssetCommand({
 				projectId: activeProject.metadata.id,
@@ -715,6 +743,7 @@ export function useEditorActions() {
 			editor.command.execute({
 				command: new BatchCommand([addMediaCommand, insertCommand]),
 			});
+			useVoiceOverStore.getState().stopRecording();
 		},
 		undefined,
 	);
diff --git a/apps/web/src/commands/timeline/track/index.ts b/apps/web/src/commands/timeline/track/index.ts
index 9d4bd9c3..4aa4ceaf 100644
--- a/apps/web/src/commands/timeline/track/index.ts
+++ b/apps/web/src/commands/timeline/track/index.ts
@@ -2,3 +2,4 @@ export { AddTrackCommand } from "./add-track";
 export { RemoveTrackCommand } from "./remove-track";
 export { ToggleTrackMuteCommand } from "./toggle-track-mute";
 export { ToggleTrackVisibilityCommand } from "./toggle-track-visibility";
+export { UpdateTrackVolumeCommand } from "./update-track-volume";
diff --git a/apps/web/src/commands/timeline/track/update-track-volume.ts b/apps/web/src/commands/timeline/track/update-track-volume.ts
new file mode 100644
index 00000000..ecd7f6ac
--- /dev/null
+++ b/apps/web/src/commands/timeline/track/update-track-volume.ts
@@ -0,0 +1,38 @@
+import { Command, type CommandResult } from "@/commands/base-command";
+import { EditorCore } from "@/core";
+import type { SceneTracks } from "@/timeline";
+import { canTrackHaveAudio, updateTrackInSceneTracks } from "@/timeline";
+import { clampDb } from "@/timeline/audio-state";
+
+export class UpdateTrackVolumeCommand extends Command {
+	private savedState: SceneTracks | null = null;
+
+	constructor({ trackId, volume }: { trackId: string; volume: number }) {
+		super();
+		this.trackId = trackId;
+		this.volume = clampDb(volume);
+	}
+
+	private trackId: string;
+	private volume: number;
+
+	execute(): CommandResult | undefined {
+		const editor = EditorCore.getInstance();
+		this.savedState = editor.scenes.getActiveScene().tracks;
+		const updatedTracks = updateTrackInSceneTracks({
+			tracks: this.savedState,
+			trackId: this.trackId,
+			update: (track) =>
+				canTrackHaveAudio(track) ? { ...track, volume: this.volume } : track,
+		});
+		editor.timeline.updateTracks(updatedTracks);
+		return undefined;
+	}
+
+	undo(): void {
+		if (this.savedState) {
+			const editor = EditorCore.getInstance();
+			editor.timeline.updateTracks(this.savedState);
+		}
+	}
+}
diff --git a/apps/web/src/components/editor/panels/assets/index.tsx b/apps/web/src/components/editor/panels/assets/index.tsx
index c0204b12..6e134eda 100644
--- a/apps/web/src/components/editor/panels/assets/index.tsx
+++ b/apps/web/src/components/editor/panels/assets/index.tsx
@@ -1,10 +1,14 @@
 "use client";
 
 import { Separator } from "@/components/ui/separator";
-import { type Tab, useAssetsPanelStore } from "@/components/editor/panels/assets/assets-panel-store";
+import {
+	type Tab,
+	useAssetsPanelStore,
+} from "@/components/editor/panels/assets/assets-panel-store";
 import { TabBar } from "./tabbar";
 import { MediaView } from "./views/assets";
 import { SettingsView } from "./views/settings";
+import { TransitionsView } from "./views/transitions";
 import { SoundsView } from "@/sounds/components/assets-view";
 import { StickersView } from "@/stickers/components/assets-view";
 import { TextView } from "@/text/components/assets-view";
@@ -21,11 +25,7 @@ export function AssetsPanel() {
 		stickers: FEATURES.stickers ? <StickersView /> : null,
 		effects: FEATURES.effects ? <EffectsView category="effect" /> : null,
 		lens: FEATURES.effects ? <EffectsView category="lens" /> : null,
-		transitions: (
-			<div className="text-muted-foreground p-4">
-				Transitions view coming soon...
-			</div>
-		),
+		transitions: <TransitionsView />,
 		settings: <SettingsView />,
 	};
 
diff --git a/apps/web/src/components/editor/panels/assets/views/transitions.tsx b/apps/web/src/components/editor/panels/assets/views/transitions.tsx
new file mode 100644
index 00000000..e0236a2f
--- /dev/null
+++ b/apps/web/src/components/editor/panels/assets/views/transitions.tsx
@@ -0,0 +1,258 @@
+"use client";
+
+import {
+	ArrowRightDoubleIcon,
+	MagicWand05Icon,
+} from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { PanelView } from "./base-panel";
+import { Button } from "@/components/ui/button";
+import { useEditor } from "@/editor/use-editor";
+import { useElementSelection } from "@/timeline/hooks/element/use-element-selection";
+import { isVisualElement } from "@/timeline/element-utils";
+import type { TimelineElement, TimelineTrack } from "@/timeline";
+import {
+	type TransitionKind,
+	withVisualTransitionParams,
+} from "@/rendering/transition";
+
+const transitions: Array<{
+	kind: TransitionKind;
+	name: string;
+	description: string;
+	inDuration: number;
+	outDuration: number;
+}> = [
+	{
+		kind: "fade",
+		name: "Soft fade",
+		description: "Clean dissolve for slides and stills.",
+		inDuration: 0.35,
+		outDuration: 0,
+	},
+	{
+		kind: "push-left",
+		name: "Slide left",
+		description: "Deck-like horizontal slide motion.",
+		inDuration: 0.45,
+		outDuration: 0,
+	},
+	{
+		kind: "push-right",
+		name: "Slide right",
+		description: "Reverse horizontal slide motion.",
+		inDuration: 0.45,
+		outDuration: 0,
+	},
+	{
+		kind: "zoom",
+		name: "Zoom in",
+		description: "Subtle punch-in with a fade edge.",
+		inDuration: 0.4,
+		outDuration: 0,
+	},
+	{
+		kind: "zoom-out",
+		name: "Zoom out",
+		description: "Settle inward from a wider opening.",
+		inDuration: 0.4,
+		outDuration: 0,
+	},
+	{
+		kind: "spin",
+		name: "Spin dissolve",
+		description: "A restrained turn with a soft fade.",
+		inDuration: 0.45,
+		outDuration: 0,
+	},
+];
+
+export function TransitionsView() {
+	const editor = useEditor();
+	const { selectedElements } = useElementSelection();
+	const scene = useEditor((currentEditor) =>
+		currentEditor.scenes.getActiveSceneOrNull(),
+	);
+	const currentTime = useEditor((currentEditor) =>
+		currentEditor.playback.getCurrentTime(),
+	);
+	const selectedVisualElements = editor.timeline
+		.getElementsWithTracks({ elements: selectedElements })
+		.filter(({ element }) => isVisualElement(element));
+	const nearestTarget = scene
+		? findNearestTransitionTarget({
+				tracks: [scene.tracks.main, ...scene.tracks.overlay],
+				currentTime,
+			})
+		: null;
+	const targets =
+		selectedVisualElements.length > 0
+			? selectedVisualElements
+			: nearestTarget
+				? [nearestTarget]
+				: [];
+	const selectedCount = selectedVisualElements.length;
+
+	const applyTransition = ({
+		kind,
+		inDuration,
+		outDuration,
+	}: {
+		kind: TransitionKind;
+		inDuration: number;
+		outDuration: number;
+	}) => {
+		if (targets.length === 0) {
+			return;
+		}
+
+		editor.timeline.updateElements({
+			updates: targets.map(({ track, element }) => ({
+				trackId: track.id,
+				elementId: element.id,
+				patch: {
+					params: withVisualTransitionParams({
+						params: element.params,
+						transitionKind: kind,
+						inDuration,
+						outDuration,
+					}),
+				},
+			})),
+		});
+	};
+
+	return (
+		<PanelView title="Transitions" contentClassName="flex flex-col gap-3 pb-3">
+			<div className="rounded-md border bg-accent/20 p-3">
+				<div className="flex items-center gap-2 text-sm font-medium">
+					<HugeiconsIcon icon={MagicWand05Icon} className="size-4" />
+					Apply at the cut
+				</div>
+				<p className="text-muted-foreground mt-1 text-xs leading-relaxed">
+					{selectedCount > 0
+						? `${selectedCount} selected clip${selectedCount === 1 ? "" : "s"}.`
+						: nearestTarget
+							? `Ready for the cut into ${nearestTarget.element.name}.`
+							: "Add at least two image or video clips to one track."}
+				</p>
+			</div>
+
+			<div className="grid grid-cols-1 gap-2">
+				{transitions.map((transition) => (
+					<TransitionCard
+						key={transition.kind}
+						transition={transition}
+						disabled={targets.length === 0}
+						onApply={applyTransition}
+					/>
+				))}
+			</div>
+		</PanelView>
+	);
+}
+
+function findNearestTransitionTarget({
+	tracks,
+	currentTime,
+}: {
+	tracks: TimelineTrack[];
+	currentTime: number;
+}): { track: TimelineTrack; element: TimelineElement } | null {
+	let nearest: { track: TimelineTrack; element: TimelineElement } | null = null;
+	let nearestDistance = Number.POSITIVE_INFINITY;
+	for (const track of tracks) {
+		const elements = track.elements
+			.filter((element) => element.type === "video" || element.type === "image")
+			.slice()
+			.sort((left, right) => left.startTime - right.startTime);
+		for (let index = 1; index < elements.length; index += 1) {
+			const element = elements[index];
+			const distance = Math.abs(element.startTime - currentTime);
+			if (distance < nearestDistance) {
+				nearest = { track, element };
+				nearestDistance = distance;
+			}
+		}
+	}
+	return nearest;
+}
+
+function TransitionCard({
+	transition,
+	disabled,
+	onApply,
+}: {
+	transition: (typeof transitions)[number];
+	disabled: boolean;
+	onApply: (transition: (typeof transitions)[number]) => void;
+}) {
+	const editor = useEditor();
+	return (
+		<Button
+			variant="outline"
+			className="group h-auto justify-start overflow-hidden p-0 text-left"
+			draggable
+			aria-disabled={disabled}
+			onClick={() => onApply(transition)}
+			onDragStart={(event) =>
+				editor.timeline.dragSource.begin({
+					dataTransfer: event.dataTransfer,
+					dragData: {
+						type: "transition",
+						id: transition.kind,
+						name: transition.name,
+						transitionKind: transition.kind,
+						inDuration: transition.inDuration,
+						outDuration: transition.outDuration,
+					},
+				})
+			}
+			onDragEnd={() => editor.timeline.dragSource.end()}
+		>
+			<div className="flex w-full items-center gap-3 p-2">
+				<TransitionPreview kind={transition.kind} />
+				<div className="min-w-0 flex-1">
+					<div className="text-sm font-medium">{transition.name}</div>
+					<div className="text-muted-foreground text-xs leading-snug">
+						{transition.description}
+					</div>
+				</div>
+			</div>
+		</Button>
+	);
+}
+
+function TransitionPreview({ kind }: { kind: TransitionKind }) {
+	return (
+		<div className="relative h-14 w-20 shrink-0 overflow-hidden rounded-sm border bg-background">
+			<div className="absolute inset-0 bg-linear-to-br from-accent via-background to-primary/20" />
+			<div className="absolute left-2 top-2 h-8 w-8 rounded-sm bg-foreground/80 shadow-sm" />
+			<div className="absolute bottom-2 right-2 h-8 w-8 rounded-sm bg-primary/80 shadow-sm" />
+			{kind === "fade" && (
+				<div className="absolute inset-0 bg-linear-to-r from-transparent via-background/20 to-background/70" />
+			)}
+			{kind === "push-left" && (
+				<HugeiconsIcon
+					icon={ArrowRightDoubleIcon}
+					className="absolute left-1/2 top-1/2 size-5 -translate-x-1/2 -translate-y-1/2 text-background drop-shadow"
+				/>
+			)}
+			{kind === "push-right" && (
+				<HugeiconsIcon
+					icon={ArrowRightDoubleIcon}
+					className="absolute left-1/2 top-1/2 size-5 -translate-x-1/2 -translate-y-1/2 rotate-180 text-background drop-shadow"
+				/>
+			)}
+			{kind === "zoom" && (
+				<div className="absolute left-1/2 top-1/2 size-10 -translate-x-1/2 -translate-y-1/2 rounded-full border border-primary/80 shadow-[0_0_24px_var(--primary)]" />
+			)}
+			{kind === "zoom-out" && (
+				<div className="absolute left-1/2 top-1/2 size-7 -translate-x-1/2 -translate-y-1/2 rounded-full border border-primary/80 shadow-[0_0_18px_var(--primary)]" />
+			)}
+			{kind === "spin" && (
+				<div className="absolute left-1/2 top-1/2 size-9 -translate-x-1/2 -translate-y-1/2 rotate-12 rounded-sm border border-primary/80 shadow-[0_0_18px_var(--primary)]" />
+			)}
+		</div>
+	);
+}
diff --git a/apps/web/src/components/editor/panels/properties/components/track-audio-properties.tsx b/apps/web/src/components/editor/panels/properties/components/track-audio-properties.tsx
new file mode 100644
index 00000000..4738d902
--- /dev/null
+++ b/apps/web/src/components/editor/panels/properties/components/track-audio-properties.tsx
@@ -0,0 +1,158 @@
+"use client";
+
+import { useEffect, useRef, useState } from "react";
+import { MusicNote03Icon } from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { NumberField } from "@/components/ui/number-field";
+import { Slider } from "@/components/ui/slider";
+import { Switch } from "@/components/ui/switch";
+import {
+	Section,
+	SectionContent,
+	SectionField,
+	SectionFields,
+} from "@/components/section";
+import { useEditor } from "@/editor/use-editor";
+import type { AudioTrack, VideoTrack } from "@/timeline";
+import { clampDb, getTrackVolume } from "@/timeline/audio-state";
+import { VOLUME_DB_MAX, VOLUME_DB_MIN } from "@/timeline/audio-constants";
+import {
+	formatNumberForDisplay,
+	getFractionDigitsForStep,
+	snapToStep,
+} from "@/utils/math";
+
+const VOLUME_STEP = 0.1;
+const VOLUME_FRACTION_DIGITS = getFractionDigitsForStep({ step: VOLUME_STEP });
+
+function normalizeVolume(value: number): number {
+	return clampDb(snapToStep({ value, step: VOLUME_STEP }));
+}
+
+function formatVolume(value: number): string {
+	return formatNumberForDisplay({
+		value,
+		maxFractionDigits: VOLUME_FRACTION_DIGITS,
+	});
+}
+
+export function TrackAudioProperties({
+	track,
+}: {
+	track: AudioTrack | VideoTrack;
+}) {
+	const editor = useEditor();
+	const sourceVolume = getTrackVolume({ track });
+	const [volume, setVolume] = useState(sourceVolume);
+	const [volumeDraft, setVolumeDraft] = useState(formatVolume(sourceVolume));
+	const textEditingRef = useRef(false);
+	const sliderEditingRef = useRef(false);
+	const previousTrackIdRef = useRef(track.id);
+
+	useEffect(() => {
+		const trackChanged = previousTrackIdRef.current !== track.id;
+		if (trackChanged) {
+			previousTrackIdRef.current = track.id;
+			textEditingRef.current = false;
+			sliderEditingRef.current = false;
+		}
+		if (!trackChanged && (textEditingRef.current || sliderEditingRef.current)) {
+			return;
+		}
+		setVolume(sourceVolume);
+		setVolumeDraft(formatVolume(sourceVolume));
+	}, [sourceVolume, track.id]);
+
+	const commitVolume = (nextVolume: number) => {
+		const normalized = normalizeVolume(nextVolume);
+		setVolume(normalized);
+		setVolumeDraft(formatVolume(normalized));
+		if (normalized !== sourceVolume) {
+			editor.timeline.updateTrackVolume({
+				trackId: track.id,
+				volume: normalized,
+			});
+		}
+	};
+
+	const commitVolumeDraft = () => {
+		textEditingRef.current = false;
+		const parsed = parseFloat(volumeDraft);
+		if (Number.isNaN(parsed)) {
+			setVolume(sourceVolume);
+			setVolumeDraft(formatVolume(sourceVolume));
+			return;
+		}
+		commitVolume(parsed);
+	};
+
+	return (
+		<div className="flex min-h-full flex-col">
+			<div className="flex h-12 shrink-0 items-center gap-2 border-b px-4">
+				<div className="flex size-7 items-center justify-center rounded-md bg-accent">
+					<HugeiconsIcon icon={MusicNote03Icon} className="size-4" />
+				</div>
+				<div className="min-w-0">
+					<div className="truncate text-sm font-medium">{track.name}</div>
+					<div className="text-muted-foreground text-xs">Track audio</div>
+				</div>
+			</div>
+			<Section sectionKey={`track-audio:${track.id}`}>
+				<SectionContent className="pt-4">
+					<SectionFields>
+						<SectionField label="Volume">
+							<div className="flex items-center gap-3">
+								<Slider
+									className="min-w-0 flex-1"
+									aria-label={`${track.name} volume`}
+									value={[volume]}
+									min={VOLUME_DB_MIN}
+									max={VOLUME_DB_MAX}
+									step={VOLUME_STEP}
+									onValueChange={(values) => {
+										sliderEditingRef.current = true;
+										const nextVolume = normalizeVolume(values[0]);
+										setVolume(nextVolume);
+										setVolumeDraft(formatVolume(nextVolume));
+									}}
+									onValueCommit={(values) => {
+										sliderEditingRef.current = false;
+										commitVolume(values[0]);
+									}}
+								/>
+								<NumberField
+									className="w-24 shrink-0"
+									aria-label={`${track.name} volume in decibels`}
+									value={volumeDraft}
+									min={VOLUME_DB_MIN}
+									max={VOLUME_DB_MAX}
+									step={VOLUME_STEP}
+									onFocus={() => {
+										textEditingRef.current = true;
+									}}
+									onChange={(event) => {
+										const nextDraft = event.currentTarget.value;
+										setVolumeDraft(nextDraft);
+										const parsed = parseFloat(nextDraft);
+										if (!Number.isNaN(parsed)) {
+											setVolume(normalizeVolume(parsed));
+										}
+									}}
+									onBlur={commitVolumeDraft}
+								/>
+							</div>
+						</SectionField>
+						<SectionField label="Muted">
+							<Switch
+								checked={track.muted}
+								onCheckedChange={() => {
+									editor.timeline.toggleTrackMute({ trackId: track.id });
+								}}
+							/>
+						</SectionField>
+					</SectionFields>
+				</SectionContent>
+			</Section>
+		</div>
+	);
+}
diff --git a/apps/web/src/components/editor/panels/properties/index.tsx b/apps/web/src/components/editor/panels/properties/index.tsx
index d946027d..f4ce9651 100644
--- a/apps/web/src/components/editor/panels/properties/index.tsx
+++ b/apps/web/src/components/editor/panels/properties/index.tsx
@@ -14,13 +14,32 @@ import { usePropertiesStore } from "./stores/properties-store";
 import { getPropertiesConfig } from "./registry";
 import { cn } from "@/utils/ui";
 import { EmptyView } from "./empty-view";
+import { TrackAudioProperties } from "./components/track-audio-properties";
 
 export function PropertiesPanel() {
 	const editor = useEditor();
 	useEditor((e) => e.scenes.getActiveSceneOrNull());
 	useEditor((e) => e.media.getAssets());
 	const { selectedElements } = useElementSelection();
-	const { activeTabPerType, setActiveTab } = usePropertiesStore();
+	const { activeTabPerType, setActiveTab, selectedTrackId } =
+		usePropertiesStore();
+	const selectedTrack = selectedTrackId
+		? editor.timeline.getTrackById({ trackId: selectedTrackId })
+		: null;
+
+	if (
+		selectedElements.length === 0 &&
+		selectedTrack &&
+		(selectedTrack.type === "audio" || selectedTrack.type === "video")
+	) {
+		return (
+			<div className="panel bg-background flex h-full overflow-hidden rounded-sm border">
+				<ScrollArea className="flex-1 scrollbar-hidden">
+					<TrackAudioProperties key={selectedTrack.id} track={selectedTrack} />
+				</ScrollArea>
+			</div>
+		);
+	}
 
 	if (selectedElements.length === 0) {
 		return (
diff --git a/apps/web/src/components/editor/panels/properties/registry.tsx b/apps/web/src/components/editor/panels/properties/registry.tsx
index 15f010f7..805098f8 100644
--- a/apps/web/src/components/editor/panels/properties/registry.tsx
+++ b/apps/web/src/components/editor/panels/properties/registry.tsx
@@ -23,7 +23,10 @@ import {
 	DashboardSpeed02Icon,
 } from "@hugeicons/core-free-icons";
 import { ElementParamsTab } from "./components/element-params-tab";
-import { ClipEffectsTab, StandaloneEffectTab } from "@/effects/components/effects-tab";
+import {
+	ClipEffectsTab,
+	StandaloneEffectTab,
+} from "@/effects/components/effects-tab";
 import { MasksTab } from "@/masks/components/masks-tab";
 import { SpeedTab } from "@/speed/components/speed-tab";
 import { GraphicTab } from "@/graphics/components/graphic-tab";
@@ -40,6 +43,11 @@ const TRANSFORM_PARAM_KEYS = [
 
 const BLENDING_PARAM_KEYS = ["opacity", "blendMode"] as const;
 const AUDIO_PARAM_KEYS = ["volume", "muted"] as const;
+const TRANSITION_PARAM_KEYS = [
+	"transition.kind",
+	"transition.inDuration",
+	"transition.outDuration",
+] as const;
 const TEXT_PARAM_KEYS = [
 	"content",
 	"fontFamily",
@@ -135,6 +143,25 @@ function buildAudioTab({
 		),
 	};
 }
+function buildTransitionTab({
+	element,
+}: {
+	element: VisualElement;
+}): PropertiesTabDef {
+	return {
+		id: "transition",
+		label: "Transition",
+		icon: <HugeiconsIcon icon={MagicWand05Icon} size={16} />,
+		content: ({ trackId }) => (
+			<ElementParamsTab
+				element={element}
+				trackId={trackId}
+				paramKeys={TRANSITION_PARAM_KEYS}
+				sectionKey="transition"
+			/>
+		),
+	};
+}
 
 function buildSpeedTab({
 	element,
@@ -202,7 +229,9 @@ function buildGraphicTab({
 		id: "graphic",
 		label: "Graphic",
 		icon: <OcShapesIcon size={16} />,
-		content: ({ trackId }) => <GraphicTab element={element} trackId={trackId} />,
+		content: ({ trackId }) => (
+			<GraphicTab element={element} trackId={trackId} />
+		),
 	};
 }
 
@@ -232,6 +261,7 @@ function getTextConfig({
 			buildTextTab({ element }),
 			buildTransformTab({ element }),
 			buildBlendingTab({ element }),
+			buildTransitionTab({ element }),
 		],
 	};
 }
@@ -251,6 +281,7 @@ function getVideoConfig({
 			...(showAudioTab ? [buildAudioTab({ element })] : []),
 			buildSpeedTab({ element }),
 			buildBlendingTab({ element }),
+			buildTransitionTab({ element }),
 			buildMasksTab({ element }),
 			...(FEATURES.effects ? [buildClipEffectsTab({ element })] : []),
 		],
@@ -267,6 +298,7 @@ function getImageConfig({
 		tabs: [
 			buildTransformTab({ element }),
 			buildBlendingTab({ element }),
+			buildTransitionTab({ element }),
 			buildMasksTab({ element }),
 			...(FEATURES.effects ? [buildClipEffectsTab({ element })] : []),
 		],
@@ -283,6 +315,7 @@ function getStickerConfig({
 		tabs: [
 			buildTransformTab({ element }),
 			buildBlendingTab({ element }),
+			buildTransitionTab({ element }),
 			...(FEATURES.effects ? [buildClipEffectsTab({ element })] : []),
 		],
 	};
@@ -299,6 +332,7 @@ function getGraphicConfig({
 			buildGraphicTab({ element }),
 			buildTransformTab({ element }),
 			buildBlendingTab({ element }),
+			buildTransitionTab({ element }),
 			buildMasksTab({ element }),
 			...(FEATURES.effects ? [buildClipEffectsTab({ element })] : []),
 		],
diff --git a/apps/web/src/components/editor/panels/properties/stores/properties-store.ts b/apps/web/src/components/editor/panels/properties/stores/properties-store.ts
index f6304349..3303dae2 100644
--- a/apps/web/src/components/editor/panels/properties/stores/properties-store.ts
+++ b/apps/web/src/components/editor/panels/properties/stores/properties-store.ts
@@ -1,19 +1,25 @@
-import { create } from "zustand";
-
-interface PropertiesState {
-	activeTabPerType: Record<string, string>;
-	setActiveTab: (args: { elementType: string; tabId: string }) => void;
-	isTransformScaleLocked: boolean;
-	setTransformScaleLocked: (args: { locked: boolean }) => void;
-}
-
-export const usePropertiesStore = create<PropertiesState>()((set) => ({
-	activeTabPerType: {},
-	setActiveTab: ({ elementType, tabId }) =>
-		set((state) => ({
-			activeTabPerType: { ...state.activeTabPerType, [elementType]: tabId },
-		})),
-	isTransformScaleLocked: false,
-	setTransformScaleLocked: ({ locked }) =>
-		set({ isTransformScaleLocked: locked }),
-}));
+import { create } from "zustand";
+
+interface PropertiesState {
+	activeTabPerType: Record<string, string>;
+	setActiveTab: (args: { elementType: string; tabId: string }) => void;
+	isTransformScaleLocked: boolean;
+	setTransformScaleLocked: (args: { locked: boolean }) => void;
+	selectedTrackId: string | null;
+	selectTrack: ({ trackId }: { trackId: string }) => void;
+	clearTrackSelection: () => void;
+}
+
+export const usePropertiesStore = create<PropertiesState>()((set) => ({
+	activeTabPerType: {},
+	setActiveTab: ({ elementType, tabId }) =>
+		set((state) => ({
+			activeTabPerType: { ...state.activeTabPerType, [elementType]: tabId },
+		})),
+	isTransformScaleLocked: false,
+	setTransformScaleLocked: ({ locked }) =>
+		set({ isTransformScaleLocked: locked }),
+	selectedTrackId: null,
+	selectTrack: ({ trackId }) => set({ selectedTrackId: trackId }),
+	clearTrackSelection: () => set({ selectedTrackId: null }),
+}));
diff --git a/apps/web/src/components/ui/slider.tsx b/apps/web/src/components/ui/slider.tsx
index aa14dfbd..35faf7e8 100644
--- a/apps/web/src/components/ui/slider.tsx
+++ b/apps/web/src/components/ui/slider.tsx
@@ -1,30 +1,33 @@
-"use client";
-
-import * as React from "react";
-import { Slider as SliderPrimitive } from "radix-ui";
-
-import { cn } from "@/utils/ui";
-
-const Slider = React.forwardRef<
-	React.ElementRef<typeof SliderPrimitive.Root>,
-	React.ComponentPropsWithoutRef<typeof SliderPrimitive.Root> & {
-		className?: string;
-	}
->(({ className, ...props }, ref) => (
-	<SliderPrimitive.Root
-		ref={ref}
-		className={cn(
-			"relative flex w-full touch-none items-center select-none",
-			className,
-		)}
-		{...props}
-	>
-		<SliderPrimitive.Track className="bg-accent relative h-1.5 w-full grow overflow-hidden rounded-full">
-			<SliderPrimitive.Range className="bg-primary absolute h-full" />
-		</SliderPrimitive.Track>
-		<SliderPrimitive.Thumb className="border-primary/50 bg-background focus-visible:ring-ring block size-4 rounded-full border shadow-sm focus-visible:ring-1 focus-visible:outline-hidden disabled:pointer-events-none disabled:opacity-50" />
-	</SliderPrimitive.Root>
-));
-Slider.displayName = SliderPrimitive.Root.displayName;
-
-export { Slider };
+"use client";
+
+import * as React from "react";
+import { Slider as SliderPrimitive } from "radix-ui";
+
+import { cn } from "@/utils/ui";
+
+const Slider = React.forwardRef<
+	React.ElementRef<typeof SliderPrimitive.Root>,
+	React.ComponentPropsWithoutRef<typeof SliderPrimitive.Root> & {
+		className?: string;
+	}
+>(({ className, ...props }, ref) => (
+	<SliderPrimitive.Root
+		ref={ref}
+		className={cn(
+			"relative flex w-full touch-none items-center select-none",
+			className,
+		)}
+		{...props}
+	>
+		<SliderPrimitive.Track className="bg-accent relative h-1.5 w-full grow overflow-hidden rounded-full">
+			<SliderPrimitive.Range className="bg-primary absolute h-full" />
+		</SliderPrimitive.Track>
+		<SliderPrimitive.Thumb
+			aria-label={props["aria-label"]}
+			className="border-primary/50 bg-background focus-visible:ring-ring block size-4 rounded-full border shadow-sm focus-visible:ring-1 focus-visible:outline-hidden disabled:pointer-events-none disabled:opacity-50"
+		/>
+	</SliderPrimitive.Root>
+));
+Slider.displayName = SliderPrimitive.Root.displayName;
+
+export { Slider };
diff --git a/apps/web/src/core/managers/audio-manager.ts b/apps/web/src/core/managers/audio-manager.ts
index d0716aad..59e3ba80 100644
--- a/apps/web/src/core/managers/audio-manager.ts
+++ b/apps/web/src/core/managers/audio-manager.ts
@@ -497,6 +497,7 @@ export class AudioManager {
 		const points = buildAudioGainAutomation({
 			element: clip.timelineElement,
 			fromLocalTime: startLocalTime,
+			trackVolume: clip.trackVolume,
 			toLocalTime: clip.duration,
 		});
 
diff --git a/apps/web/src/core/managers/timeline-manager.ts b/apps/web/src/core/managers/timeline-manager.ts
index 6fb28625..82987200 100644
--- a/apps/web/src/core/managers/timeline-manager.ts
+++ b/apps/web/src/core/managers/timeline-manager.ts
@@ -34,6 +34,7 @@ import {
 	RemoveTrackCommand,
 	ToggleTrackMuteCommand,
 	ToggleTrackVisibilityCommand,
+	UpdateTrackVolumeCommand,
 	InsertElementCommand,
 	DeleteElementsCommand,
 	DuplicateElementsCommand,
@@ -178,6 +179,16 @@ export class TimelineManager {
 		const command = new ToggleTrackMuteCommand(trackId);
 		this.editor.command.execute({ command });
 	}
+	updateTrackVolume({
+		trackId,
+		volume,
+	}: {
+		trackId: string;
+		volume: number;
+	}): void {
+		const command = new UpdateTrackVolumeCommand({ trackId, volume });
+		this.editor.command.execute({ command });
+	}
 
 	toggleTrackVisibility({ trackId }: { trackId: string }): void {
 		const command = new ToggleTrackVisibilityCommand(trackId);
@@ -841,7 +852,9 @@ export class TimelineManager {
 	}): void {
 		const shouldMute = elements.some(({ trackId, elementId }) => {
 			const element = this.getElementByRef({ trackId, elementId });
-			return element && canElementHaveAudio(element) && !isElementMuted({ element });
+			return (
+				element && canElementHaveAudio(element) && !isElementMuted({ element })
+			);
 		});
 
 		const nextUpdates = elements.flatMap(({ trackId, elementId }) => {
diff --git a/apps/web/src/media/audio.ts b/apps/web/src/media/audio.ts
index 7abaf90e..0e8ee826 100644
--- a/apps/web/src/media/audio.ts
+++ b/apps/web/src/media/audio.ts
@@ -10,6 +10,7 @@ import type { MediaAsset } from "@/media/types";
 import { applyAudioMasteringToBuffer } from "@/media/audio-mastering";
 import type { AudioCapableElement } from "@/timeline/audio-state";
 import {
+	getTrackVolume,
 	hasAnimatedVolume,
 	isElementMuted,
 	resolveEffectiveAudioGain,
@@ -21,10 +22,7 @@ import { mediaSupportsAudio } from "@/media/media-utils";
 import { getSourceTimeAtClipTime, renderRetimedBuffer } from "@/retime";
 import { Input, ALL_FORMATS, BlobSource, AudioBufferSink } from "mediabunny";
 import { TICKS_PER_SECOND } from "@/wasm";
-import {
-	computeRmsBuckets,
-	type SampleBucket,
-} from "@/media/waveform-summary";
+import { computeRmsBuckets, type SampleBucket } from "@/media/waveform-summary";
 
 const MAX_AUDIO_CHANNELS = 2;
 const EXPORT_SAMPLE_RATE = 44100;
@@ -37,6 +35,7 @@ export interface CollectedAudioElement {
 	trimStart: number;
 	trimEnd: number;
 	volume: number;
+	trackVolume: number;
 	muted: boolean;
 	retime?: RetimeConfig;
 }
@@ -89,6 +88,7 @@ export async function decodeAudioToFloat32({
 export interface AudibleElementCandidate {
 	element: AudioElement | VideoElement;
 	mediaAsset: MediaAsset | null;
+	trackVolume: number;
 }
 
 export function collectAudibleCandidates({
@@ -114,7 +114,11 @@ export function collectAudibleCandidates({
 				: null;
 			if (!doesElementHaveEnabledAudio({ element, mediaAsset })) continue;
 
-			candidates.push({ element, mediaAsset });
+			candidates.push({
+				element,
+				mediaAsset,
+				trackVolume: canTrackHaveAudio(track) ? getTrackVolume({ track }) : 0,
+			});
 		}
 	}
 
@@ -148,7 +152,7 @@ export async function collectAudioElements({
 	);
 	const pendingElements: Array<Promise<CollectedAudioElement | null>> = [];
 
-	for (const { element, mediaAsset } of candidates) {
+	for (const { element, mediaAsset, trackVolume } of candidates) {
 		if (element.type === "audio") {
 			pendingElements.push(
 				resolveAudioBufferForElement({
@@ -166,10 +170,11 @@ export async function collectAudioElements({
 						trimEnd: element.trimEnd / TICKS_PER_SECOND,
 						volume: resolveEffectiveAudioGain({
 							element,
-							trackMuted: false,
+							trackVolume,
 							localTime: 0,
 						}),
 						muted: isElementMuted({ element }),
+						trackVolume,
 						retime: element.retime,
 					};
 				}),
@@ -195,10 +200,11 @@ export async function collectAudioElements({
 						trimEnd: element.trimEnd / TICKS_PER_SECOND,
 						volume: resolveEffectiveAudioGain({
 							element,
-							trackMuted: false,
+							trackVolume,
 							localTime: 0,
 						}),
 						muted: isElementMuted({ element }),
+						trackVolume,
 						retime: element.retime,
 					};
 				}),
@@ -359,6 +365,7 @@ export interface AudioClipSource {
 	trimStart: number;
 	trimEnd: number;
 	volume: number;
+	trackVolume: number;
 	muted: boolean;
 	retime?: RetimeConfig;
 }
@@ -401,10 +408,12 @@ async function fetchLibraryAudioClip({
 	element,
 	muted,
 	volume,
+	trackVolume,
 }: {
 	element: LibraryAudioElement;
 	muted: boolean;
 	volume: number;
+	trackVolume: number;
 }): Promise<AudioClipSource | null> {
 	try {
 		const response = await fetch(element.sourceUrl);
@@ -427,6 +436,7 @@ async function fetchLibraryAudioClip({
 			trimStart: element.trimStart,
 			trimEnd: element.trimEnd,
 			volume,
+			trackVolume,
 			muted,
 			retime: element.retime,
 		};
@@ -462,11 +472,13 @@ function collectMediaAudioClip({
 	mediaAsset,
 	muted,
 	volume,
+	trackVolume,
 }: {
 	element: AudioCapableElement;
 	mediaAsset: MediaAsset;
 	muted: boolean;
 	volume: number;
+	trackVolume: number;
 }): AudioClipSource {
 	return {
 		timelineElement: element,
@@ -478,6 +490,7 @@ function collectMediaAudioClip({
 		trimStart: element.trimStart / TICKS_PER_SECOND,
 		trimEnd: element.trimEnd / TICKS_PER_SECOND,
 		volume,
+		trackVolume,
 		muted,
 		retime: element.retime,
 	};
@@ -507,8 +520,12 @@ export async function collectAudioMixSources({
 				? (mediaMap.get(element.mediaId) ?? null)
 				: null;
 			if (!doesElementHaveEnabledAudio({ element, mediaAsset })) continue;
+			const trackVolume = canTrackHaveAudio(track)
+				? getTrackVolume({ track })
+				: 0;
 			const volume = resolveEffectiveAudioGain({
 				element,
+				trackVolume,
 				localTime: 0,
 			});
 
@@ -562,6 +579,9 @@ export async function collectAudioClips({
 
 	for (const track of orderedTracks) {
 		const isTrackMuted = canTrackHaveAudio(track) && track.muted;
+		const trackVolume = canTrackHaveAudio(track)
+			? getTrackVolume({ track })
+			: 0;
 
 		for (const element of track.elements) {
 			if (!canElementHaveAudio(element)) continue;
@@ -575,6 +595,7 @@ export async function collectAudioClips({
 			const volume = resolveEffectiveAudioGain({
 				element,
 				trackMuted: isTrackMuted,
+				trackVolume,
 				localTime: 0,
 			});
 
@@ -589,11 +610,12 @@ export async function collectAudioClips({
 							mediaAsset,
 							muted,
 							volume,
+							trackVolume,
 						}),
 					);
 				} else {
 					pendingLibraryClips.push(
-						fetchLibraryAudioClip({ element, muted, volume }),
+						fetchLibraryAudioClip({ element, muted, volume, trackVolume }),
 					);
 				}
 				continue;
@@ -607,6 +629,7 @@ export async function collectAudioClips({
 							mediaAsset,
 							muted,
 							volume,
+							trackVolume,
 						}),
 					);
 				}
@@ -855,6 +878,7 @@ function mixAudioChannels({
 			const gain = hasAnimatedVolume({ element: element.timelineElement })
 				? resolveEffectiveAudioGain({
 						element: element.timelineElement,
+						trackVolume: element.trackVolume,
 						localTime: clipTime,
 					})
 				: element.volume;
diff --git a/apps/web/src/params/registry.ts b/apps/web/src/params/registry.ts
index 9e363c88..6456a360 100644
--- a/apps/web/src/params/registry.ts
+++ b/apps/web/src/params/registry.ts
@@ -1,20 +1,11 @@
-import type {
-	ParamDefinition,
-	ParamValue,
-	ParamValues,
-} from "@/params";
+import type { ParamDefinition, ParamValue, ParamValues } from "@/params";
 import { MIN_TRANSFORM_SCALE } from "@/animation/transform";
 import type { BlendMode } from "@/rendering";
-import type {
-	ElementType,
-	TimelineElement,
-} from "@/timeline";
+import { TRANSITION_KIND_OPTIONS } from "@/rendering/transition";
+import type { ElementType, TimelineElement } from "@/timeline";
 import { DEFAULTS } from "@/timeline/defaults";
 import { VOLUME_DB_MAX, VOLUME_DB_MIN } from "@/timeline/audio-constants";
-import {
-	CORNER_RADIUS_MAX,
-	CORNER_RADIUS_MIN,
-} from "@/text/background";
+import { CORNER_RADIUS_MAX, CORNER_RADIUS_MIN } from "@/text/background";
 
 export type ElementParamDefinition<TKey extends string = string> =
 	ParamDefinition<TKey> & {
@@ -46,13 +37,7 @@ export class DefinitionRegistry<TKey extends string, TDefinition> {
 		this.entityName = entityName;
 	}
 
-	register({
-		key,
-		definition,
-	}: {
-		key: TKey;
-		definition: TDefinition;
-	}): void {
+	register({ key, definition }: { key: TKey; definition: TDefinition }): void {
 		this.definitions.set(key, definition);
 	}
 
@@ -153,6 +138,36 @@ const visualElementParams: ElementParamDefinition[] = [
 		options: BLEND_MODE_OPTIONS,
 	},
 ];
+const transitionElementParams: ElementParamDefinition[] = [
+	{
+		key: "transition.kind",
+		label: "Style",
+		type: "select",
+		default: DEFAULTS.element.transitionKind,
+		keyframable: false,
+		options: TRANSITION_KIND_OPTIONS,
+	},
+	{
+		key: "transition.inDuration",
+		label: "In",
+		type: "number",
+		default: DEFAULTS.element.transitionDuration,
+		min: 0,
+		max: 5,
+		step: 0.1,
+		keyframable: false,
+	},
+	{
+		key: "transition.outDuration",
+		label: "Out",
+		type: "number",
+		default: DEFAULTS.element.transitionDuration,
+		min: 0,
+		max: 5,
+		step: 0.1,
+		keyframable: false,
+	},
+];
 
 const audioElementParams: ElementParamDefinition[] = [
 	{
@@ -333,20 +348,31 @@ export const elementParamRegistry = new DefinitionRegistry<
 
 elementParamRegistry.register({
 	key: "video",
-	definition: [...visualElementParams, ...audioElementParams],
+	definition: [
+		...visualElementParams,
+		...transitionElementParams,
+		...audioElementParams,
+	],
+});
+elementParamRegistry.register({
+	key: "image",
+	definition: [...visualElementParams, ...transitionElementParams],
 });
-elementParamRegistry.register({ key: "image", definition: visualElementParams });
 elementParamRegistry.register({
 	key: "text",
-	definition: [...textElementParams, ...visualElementParams],
+	definition: [
+		...textElementParams,
+		...visualElementParams,
+		...transitionElementParams,
+	],
 });
 elementParamRegistry.register({
 	key: "sticker",
-	definition: visualElementParams,
+	definition: [...visualElementParams, ...transitionElementParams],
 });
 elementParamRegistry.register({
 	key: "graphic",
-	definition: visualElementParams,
+	definition: [...visualElementParams, ...transitionElementParams],
 });
 elementParamRegistry.register({ key: "audio", definition: audioElementParams });
 elementParamRegistry.register({ key: "effect", definition: [] });
@@ -435,4 +461,3 @@ export function buildElementParamValues({
 	}
 	return values;
 }
-
diff --git a/apps/web/src/rendering/__tests__/transition.test.ts b/apps/web/src/rendering/__tests__/transition.test.ts
new file mode 100644
index 00000000..4421fe58
--- /dev/null
+++ b/apps/web/src/rendering/__tests__/transition.test.ts
@@ -0,0 +1,166 @@
+import { describe, expect, test } from "bun:test";
+import {
+	applyVisualTransition,
+	buildTransitionFromParams,
+} from "@/rendering/transition";
+import type { Transform } from "@/rendering";
+import { TICKS_PER_SECOND } from "@/wasm";
+
+const baseTransform: Transform = {
+	scaleX: 1,
+	scaleY: 1,
+	position: { x: 0, y: 0 },
+	rotate: 0,
+};
+
+describe("visual transitions", () => {
+	test("fade ramps opacity at clip edges", () => {
+		const transition = buildTransitionFromParams({
+			params: {
+				"transition.kind": "fade",
+				"transition.inDuration": 1,
+				"transition.outDuration": 1,
+			},
+		});
+
+		expect(
+			applyVisualTransition({
+				baseTransform,
+				transition,
+				localTime: 0,
+				duration: 4 * TICKS_PER_SECOND,
+				canvasWidth: 100,
+			}).opacityMultiplier,
+		).toBe(0);
+		expect(
+			applyVisualTransition({
+				baseTransform,
+				transition,
+				localTime: 2 * TICKS_PER_SECOND,
+				duration: 4 * TICKS_PER_SECOND,
+				canvasWidth: 100,
+			}).opacityMultiplier,
+		).toBe(1);
+		expect(
+			applyVisualTransition({
+				baseTransform,
+				transition,
+				localTime: 4 * TICKS_PER_SECOND,
+				duration: 4 * TICKS_PER_SECOND,
+				canvasWidth: 100,
+			}).opacityMultiplier,
+		).toBe(0);
+	});
+
+	test("slide left moves in and out across canvas", () => {
+		const transition = buildTransitionFromParams({
+			params: {
+				"transition.kind": "push-left",
+				"transition.inDuration": 1,
+				"transition.outDuration": 1,
+			},
+		});
+
+		const enter = applyVisualTransition({
+			baseTransform,
+			transition,
+			localTime: 0,
+			duration: 4 * TICKS_PER_SECOND,
+			canvasWidth: 100,
+		});
+		const middle = applyVisualTransition({
+			baseTransform,
+			transition,
+			localTime: 2 * TICKS_PER_SECOND,
+			duration: 4 * TICKS_PER_SECOND,
+			canvasWidth: 100,
+		});
+		const leave = applyVisualTransition({
+			baseTransform,
+			transition,
+			localTime: 4 * TICKS_PER_SECOND,
+			duration: 4 * TICKS_PER_SECOND,
+			canvasWidth: 100,
+		});
+
+		expect(enter.transform.position.x).toBe(100);
+		expect(middle.transform.position.x).toBe(0);
+		expect(leave.transform.position.x).toBe(-100);
+		expect(leave.opacityMultiplier).toBe(1);
+	});
+
+	test("slide right mirrors horizontal entry and exit", () => {
+		const transition = buildTransitionFromParams({
+			params: {
+				"transition.kind": "push-right",
+				"transition.inDuration": 1,
+				"transition.outDuration": 1,
+			},
+		});
+
+		const enter = applyVisualTransition({
+			baseTransform,
+			transition,
+			localTime: 0,
+			duration: 4 * TICKS_PER_SECOND,
+			canvasWidth: 100,
+		});
+		const middle = applyVisualTransition({
+			baseTransform,
+			transition,
+			localTime: 2 * TICKS_PER_SECOND,
+			duration: 4 * TICKS_PER_SECOND,
+			canvasWidth: 100,
+		});
+		const leave = applyVisualTransition({
+			baseTransform,
+			transition,
+			localTime: 4 * TICKS_PER_SECOND,
+			duration: 4 * TICKS_PER_SECOND,
+			canvasWidth: 100,
+		});
+
+		expect(enter.transform.position.x).toBe(-100);
+		expect(middle.transform.position.x).toBe(0);
+		expect(leave.transform.position.x).toBe(100);
+		expect(enter.opacityMultiplier).toBe(1);
+	});
+
+	test("zoom and spin variants converge on the base transform", () => {
+		const applyKind = ({
+			kind,
+			localTime,
+		}: {
+			kind: "zoom" | "zoom-out" | "spin";
+			localTime: number;
+		}) =>
+			applyVisualTransition({
+				baseTransform,
+				transition: buildTransitionFromParams({
+					params: {
+						"transition.kind": kind,
+						"transition.inDuration": 1,
+						"transition.outDuration": 0,
+					},
+				}),
+				localTime,
+				duration: 4 * TICKS_PER_SECOND,
+				canvasWidth: 100,
+			});
+
+		expect(applyKind({ kind: "zoom", localTime: 0 }).transform.scaleX).toBe(
+			0.96,
+		);
+		expect(applyKind({ kind: "zoom-out", localTime: 0 }).transform.scaleX).toBe(
+			1.04,
+		);
+		expect(applyKind({ kind: "spin", localTime: 0 }).transform.rotate).toBe(-6);
+
+		const settledSpin = applyKind({
+			kind: "spin",
+			localTime: 2 * TICKS_PER_SECOND,
+		});
+		expect(settledSpin.transform.scaleX).toBe(1);
+		expect(settledSpin.transform.rotate).toBe(0);
+	});
+});
diff --git a/apps/web/src/rendering/transition.ts b/apps/web/src/rendering/transition.ts
new file mode 100644
index 00000000..874975a1
--- /dev/null
+++ b/apps/web/src/rendering/transition.ts
@@ -0,0 +1,194 @@
+import type { ParamValues } from "@/params";
+import { clamp } from "@/utils/math";
+import { TICKS_PER_SECOND } from "@/wasm";
+import type { Transform } from "./index";
+
+export type TransitionKind =
+	| "fade"
+	| "push-left"
+	| "push-right"
+	| "zoom"
+	| "zoom-out"
+	| "spin";
+
+export interface VisualTransition {
+	kind: TransitionKind;
+	inDuration: number;
+	outDuration: number;
+}
+
+export interface TransitionState {
+	opacityMultiplier: number;
+	transform: Transform;
+}
+
+export const TRANSITION_KIND_OPTIONS: Array<{
+	value: TransitionKind;
+	label: string;
+}> = [
+	{ value: "fade", label: "Soft fade" },
+	{ value: "push-left", label: "Slide left" },
+	{ value: "push-right", label: "Slide right" },
+	{ value: "zoom", label: "Zoom in" },
+	{ value: "zoom-out", label: "Zoom out" },
+	{ value: "spin", label: "Spin dissolve" },
+];
+
+export function isTransitionKind(value: string): value is TransitionKind {
+	return TRANSITION_KIND_OPTIONS.some((option) => option.value === value);
+}
+export function withVisualTransitionParams({
+	params,
+	transitionKind,
+	inDuration,
+	outDuration,
+}: {
+	params: ParamValues;
+	transitionKind: TransitionKind;
+	inDuration: number;
+	outDuration: number;
+}): ParamValues {
+	return {
+		...params,
+		"transition.kind": transitionKind,
+		"transition.inDuration": inDuration,
+		"transition.outDuration": outDuration,
+	};
+}
+
+export function buildTransitionFromParams({
+	params,
+}: {
+	params: ParamValues;
+}): VisualTransition {
+	const kindValue = params["transition.kind"];
+	const inDurationValue = params["transition.inDuration"];
+	const outDurationValue = params["transition.outDuration"];
+	return {
+		kind:
+			typeof kindValue === "string" && isTransitionKind(kindValue)
+				? kindValue
+				: "fade",
+		inDuration: readDuration({ value: inDurationValue }),
+		outDuration: readDuration({ value: outDurationValue }),
+	};
+}
+
+export function applyVisualTransition({
+	baseTransform,
+	transition,
+	localTime,
+	duration,
+	canvasWidth,
+}: {
+	baseTransform: Transform;
+	transition?: VisualTransition;
+	localTime: number;
+	duration: number;
+	canvasWidth: number;
+}): TransitionState {
+	if (!transition || duration <= 0) {
+		return { opacityMultiplier: 1, transform: baseTransform };
+	}
+
+	const inProgress = progressWithin({
+		elapsed: localTime,
+		duration: transition.inDuration,
+	});
+	const outProgress = progressWithin({
+		elapsed: duration - localTime,
+		duration: transition.outDuration,
+	});
+	const progress = Math.min(inProgress, outProgress);
+	const isSlide =
+		transition.kind === "push-left" || transition.kind === "push-right";
+	const opacityMultiplier = isSlide ? 1 : ease({ progress });
+	const transform = applyTransitionTransform({
+		transform: baseTransform,
+		transition,
+		inProgress,
+		outProgress,
+		canvasWidth,
+	});
+	return { opacityMultiplier, transform };
+}
+
+function readDuration({ value }: { value: unknown }): number {
+	const seconds =
+		typeof value === "number" && Number.isFinite(value)
+			? clamp({ value, min: 0, max: 5 })
+			: 0;
+	return seconds * TICKS_PER_SECOND;
+}
+
+function progressWithin({
+	elapsed,
+	duration,
+}: {
+	elapsed: number;
+	duration: number;
+}): number {
+	if (duration <= 0) {
+		return 1;
+	}
+	return clamp({ value: elapsed / duration, min: 0, max: 1 });
+}
+
+function ease({ progress }: { progress: number }): number {
+	return progress * progress * (3 - 2 * progress);
+}
+
+function applyTransitionTransform({
+	transform,
+	transition,
+	inProgress,
+	outProgress,
+	canvasWidth,
+}: {
+	transform: Transform;
+	transition: VisualTransition;
+	inProgress: number;
+	outProgress: number;
+	canvasWidth: number;
+}): Transform {
+	if (transition.kind === "fade") {
+		return transform;
+	}
+
+	if (transition.kind === "zoom" || transition.kind === "zoom-out") {
+		const progress = Math.min(inProgress, outProgress);
+		const eased = ease({ progress });
+		const scale =
+			transition.kind === "zoom" ? 0.96 + eased * 0.04 : 1.04 - eased * 0.04;
+		return {
+			...transform,
+			scaleX: transform.scaleX * scale,
+			scaleY: transform.scaleY * scale,
+		};
+	}
+
+	if (transition.kind === "spin") {
+		const progress = Math.min(inProgress, outProgress);
+		const eased = ease({ progress });
+		const scale = 0.96 + eased * 0.04;
+		return {
+			...transform,
+			scaleX: transform.scaleX * scale,
+			scaleY: transform.scaleY * scale,
+			rotate: transform.rotate - (1 - eased) * 6,
+		};
+	}
+
+	const direction = transition.kind === "push-right" ? -1 : 1;
+	const enteringOffset =
+		(1 - ease({ progress: inProgress })) * canvasWidth * direction;
+	const leavingOffset =
+		(ease({ progress: outProgress }) - 1) * canvasWidth * direction;
+	return {
+		...transform,
+		position: {
+			x: transform.position.x + enteringOffset + leavingOffset,
+			y: transform.position.y,
+		},
+	};
+}
diff --git a/apps/web/src/services/renderer/__tests__/scene-builder-transition.test.ts b/apps/web/src/services/renderer/__tests__/scene-builder-transition.test.ts
new file mode 100644
index 00000000..dd644f2a
--- /dev/null
+++ b/apps/web/src/services/renderer/__tests__/scene-builder-transition.test.ts
@@ -0,0 +1,99 @@
+import { describe, expect, test } from "bun:test";
+import { buildScene } from "@/services/renderer/scene-builder";
+import { ImageNode } from "@/services/renderer/nodes/image-node";
+import type { ImageElement, SceneTracks } from "@/timeline";
+import type { MediaAsset } from "@/media/types";
+import {
+	mediaTime,
+	type MediaTime,
+	TICKS_PER_SECOND,
+	ZERO_MEDIA_TIME,
+} from "@/wasm";
+
+function imageElement({
+	id,
+	mediaId,
+	startTime,
+	transitionDuration = 0,
+}: {
+	id: string;
+	mediaId: string;
+	startTime: MediaTime;
+	transitionDuration?: number;
+}): ImageElement {
+	return {
+		id,
+		name: id,
+		type: "image",
+		mediaId,
+		startTime,
+		duration: mediaTime({ ticks: 2 * TICKS_PER_SECOND }),
+		trimStart: ZERO_MEDIA_TIME,
+		trimEnd: ZERO_MEDIA_TIME,
+		params: {
+			"transform.positionX": 0,
+			"transform.positionY": 0,
+			"transform.scaleX": 1,
+			"transform.scaleY": 1,
+			"transform.rotate": 0,
+			opacity: 1,
+			blendMode: "normal",
+			"transition.kind": "fade",
+			"transition.inDuration": transitionDuration,
+			"transition.outDuration": 0,
+		},
+	};
+}
+
+function imageAsset(id: string): MediaAsset {
+	return {
+		id,
+		name: id,
+		type: "image",
+		file: new File([], `${id}.png`, { type: "image/png" }),
+		url: `blob:${id}`,
+	};
+}
+
+describe("scene transition boundaries", () => {
+	test("holds the outgoing slide through the incoming transition", () => {
+		const first = imageElement({
+			id: "first",
+			mediaId: "media-first",
+			startTime: ZERO_MEDIA_TIME,
+		});
+		const second = imageElement({
+			id: "second",
+			mediaId: "media-second",
+			startTime: mediaTime({ ticks: 3 * TICKS_PER_SECOND }),
+			transitionDuration: 1,
+		});
+		const tracks: SceneTracks = {
+			overlay: [],
+			main: {
+				id: "main",
+				name: "Main Track",
+				type: "video",
+				elements: [first, second],
+				muted: false,
+				hidden: false,
+			},
+			audio: [],
+		};
+		const scene = buildScene({
+			canvasSize: { width: 1920, height: 1080 },
+			tracks,
+			mediaAssets: [imageAsset("media-first"), imageAsset("media-second")],
+			duration: 5 * TICKS_PER_SECOND,
+			background: { type: "color", color: "transparent" },
+		});
+		const imageNodes = scene.children.filter(
+			(node): node is ImageNode => node instanceof ImageNode,
+		);
+
+		expect(imageNodes).toHaveLength(2);
+		expect(imageNodes[0].params.contentDuration).toBe(2 * TICKS_PER_SECOND);
+		expect(imageNodes[0].params.duration).toBe(4 * TICKS_PER_SECOND);
+		expect(imageNodes[1].params.transition?.inDuration).toBe(TICKS_PER_SECOND);
+	});
+});
diff --git a/apps/web/src/services/renderer/nodes/text-node.ts b/apps/web/src/services/renderer/nodes/text-node.ts
index 6635a031..79ed0272 100644
--- a/apps/web/src/services/renderer/nodes/text-node.ts
+++ b/apps/web/src/services/renderer/nodes/text-node.ts
@@ -2,6 +2,7 @@ import { BaseNode } from "./base-node";
 import type { TextElement } from "@/timeline";
 import type { EffectPass } from "@/effects/types";
 import type { BlendMode, Transform } from "@/rendering";
+import type { VisualTransition } from "@/rendering/transition";
 import { drawMeasuredTextLayout } from "@/text/primitives";
 import type { MeasuredTextElement } from "@/text/measure-element";
 
@@ -9,6 +10,7 @@ export type TextNodeParams = TextElement & {
 	transform: Transform;
 	opacity: number;
 	blendMode?: BlendMode;
+	transition?: VisualTransition;
 	canvasCenter: { x: number; y: number };
 	canvasHeight: number;
 	textBaseline?: CanvasTextBaseline;
diff --git a/apps/web/src/services/renderer/nodes/visual-node.ts b/apps/web/src/services/renderer/nodes/visual-node.ts
index b9bf1709..e3f9b42f 100644
--- a/apps/web/src/services/renderer/nodes/visual-node.ts
+++ b/apps/web/src/services/renderer/nodes/visual-node.ts
@@ -2,10 +2,12 @@ import { BaseNode } from "./base-node";
 import type { Effect, EffectPass } from "@/effects/types";
 import type { Mask } from "@/masks/types";
 import type { BlendMode, Transform } from "@/rendering";
+import type { VisualTransition } from "@/rendering/transition";
 import type { RetimeConfig, VisualElement } from "@/timeline";
 
 export interface VisualNodeParams {
 	duration: number;
+	contentDuration?: number;
 	timeOffset: number;
 	trimStart: number;
 	trimEnd: number;
@@ -14,6 +16,7 @@ export interface VisualNodeParams {
 	animations?: VisualElement["animations"];
 	opacity: number;
 	blendMode?: BlendMode;
+	transition?: VisualTransition;
 	effects?: Effect[];
 	masks?: Mask[];
 }
diff --git a/apps/web/src/services/renderer/resolve.ts b/apps/web/src/services/renderer/resolve.ts
index 12f57e30..54a6eca4 100644
--- a/apps/web/src/services/renderer/resolve.ts
+++ b/apps/web/src/services/renderer/resolve.ts
@@ -22,6 +22,7 @@ import {
 } from "@/text/measure-element";
 import { resolveColorAtTime, resolveOpacityAtTime } from "@/animation/values";
 import { resolveTransformAtTime } from "@/rendering/animation-values";
+import { applyVisualTransition } from "@/rendering/transition";
 import { videoCache } from "@/services/video-cache/service";
 import type { CanvasRenderer } from "./canvas-renderer";
 import type { AnyBaseNode } from "./nodes/base-node";
@@ -148,12 +149,13 @@ function resolveVisualState({
 		return null;
 	}
 
+	const contentDuration = params.contentDuration ?? params.duration;
 	const localTime = getElementLocalTime({
 		timelineTime: context.time,
 		elementStartTime: params.timeOffset,
-		elementDuration: params.duration,
+		elementDuration: contentDuration,
 	});
-	const transform = applyMotionEffects({
+	const baseTransform = applyMotionEffects({
 		baseTransform: resolveTransformAtTime({
 			baseTransform: params.transform,
 			animations: params.animations,
@@ -162,15 +164,24 @@ function resolveVisualState({
 		effects: params.effects,
 		animations: params.animations,
 		localTime,
-		duration: params.duration,
+		duration: contentDuration,
 		canvasWidth: context.renderer.width,
 		canvasHeight: context.renderer.height,
 	});
-	const opacity = resolveOpacityAtTime({
+	const baseOpacity = resolveOpacityAtTime({
 		baseOpacity: params.opacity,
 		animations: params.animations,
 		localTime,
 	});
+	const transitionState = applyVisualTransition({
+		baseTransform,
+		transition: params.transition,
+		localTime,
+		duration: contentDuration,
+		canvasWidth: context.renderer.width,
+	});
+	const transform = transitionState.transform;
+	const opacity = baseOpacity * transitionState.opacityMultiplier;
 	const containScale = Math.min(
 		context.renderer.width / sourceWidth,
 		context.renderer.height / sourceHeight,
@@ -207,17 +218,21 @@ async function resolveVideoNode({
 	if (clipTime < 0 || clipTime >= node.params.duration) {
 		return null;
 	}
+	const contentDuration = node.params.contentDuration ?? node.params.duration;
+	const sourceClipTime = Math.min(clipTime, Math.max(0, contentDuration - 1));
 
 	const sourceTimeTicks =
 		node.params.trimStart +
 		getSourceTimeAtClipTime({
-			clipTime,
+			clipTime: sourceClipTime,
 			retime: node.params.retime,
 		});
 	const frame = await videoCache.getFrameAt({
 		mediaId: node.params.mediaId,
 		file: node.params.file,
-		time: mediaTimeToSeconds({ time: roundMediaTime({ time: sourceTimeTicks }) }),
+		time: mediaTimeToSeconds({
+			time: roundMediaTime({ time: sourceTimeTicks }),
+		}),
 	});
 	if (!frame) {
 		return null;
@@ -344,18 +359,27 @@ function resolveTextNode({
 		elementDuration: node.params.duration,
 	});
 	const background = buildTextBackgroundFromElement({ element: node.params });
+	const baseTransform = resolveTransformAtTime({
+		baseTransform: node.params.transform,
+		animations: node.params.animations,
+		localTime,
+	});
+	const baseOpacity = resolveOpacityAtTime({
+		baseOpacity: node.params.opacity,
+		animations: node.params.animations,
+		localTime,
+	});
+	const transitionState = applyVisualTransition({
+		baseTransform,
+		transition: node.params.transition,
+		localTime,
+		duration: node.params.duration,
+		canvasWidth: context.renderer.width,
+	});
 
 	return {
-		transform: resolveTransformAtTime({
-			baseTransform: node.params.transform,
-			animations: node.params.animations,
-			localTime,
-		}),
-		opacity: resolveOpacityAtTime({
-			baseOpacity: node.params.opacity,
-			animations: node.params.animations,
-			localTime,
-		}),
+		transform: transitionState.transform,
+		opacity: baseOpacity * transitionState.opacityMultiplier,
 		textColor: resolveColorAtTime({
 			baseColor:
 				typeof node.params.params.color === "string"
@@ -438,7 +462,9 @@ async function resolveBackdropSource({
 		const frame = await videoCache.getFrameAt({
 			mediaId: node.params.mediaId,
 			file: node.params.file,
-			time: mediaTimeToSeconds({ time: roundMediaTime({ time: sourceTimeTicks }) }),
+			time: mediaTimeToSeconds({
+				time: roundMediaTime({ time: sourceTimeTicks }),
+			}),
 		});
 		if (!frame) {
 			return null;
@@ -485,10 +511,9 @@ function resolveEffectLayerNode({
 	const motion = definition.motion?.evaluate({
 		effectParams: node.params.effectParams,
 		progress: sampleEasingBezier({
-			bezier:
-				BUILTIN_PRESETS.find(
-					(entry) => entry.id === node.params.effectParams.easing,
-				)?.value ?? [0.25, 0.1, 0.25, 1],
+			bezier: BUILTIN_PRESETS.find(
+				(entry) => entry.id === node.params.effectParams.easing,
+			)?.value ?? [0.25, 0.1, 0.25, 1],
 			x: clamp({
 				value: (time - node.params.timeOffset) / node.params.duration,
 				min: 0,
diff --git a/apps/web/src/services/renderer/scene-builder.ts b/apps/web/src/services/renderer/scene-builder.ts
index 431b8269..9df154ef 100644
--- a/apps/web/src/services/renderer/scene-builder.ts
+++ b/apps/web/src/services/renderer/scene-builder.ts
@@ -1,4 +1,4 @@
-import type { SceneTracks, TimelineTrack } from "@/timeline";
+import type { SceneTracks, TimelineElement, TimelineTrack } from "@/timeline";
 import type { MediaAsset } from "@/media/types";
 import { RootNode } from "./nodes/root-node";
 import { VideoNode } from "./nodes/video-node";
@@ -17,6 +17,7 @@ import {
 	readBlendModeFromParams,
 	readOpacityFromParams,
 } from "@/rendering";
+import { buildTransitionFromParams } from "@/rendering/transition";
 
 const PREVIEW_MAX_IMAGE_SIZE = 2048;
 
@@ -29,6 +30,32 @@ function getVisibleSortedElements({ track }: { track: TimelineTrack }) {
 			return a.id.localeCompare(b.id);
 		});
 }
+function getTailHoldDuration({
+	elements,
+	elementIndex,
+}: {
+	elements: TimelineElement[];
+	elementIndex: number;
+}): number {
+	const element = elements[elementIndex];
+	const nextElement = elements[elementIndex + 1];
+	if (
+		!element ||
+		!nextElement ||
+		(element.type !== "video" && element.type !== "image") ||
+		(nextElement.type !== "video" && nextElement.type !== "image")
+	) {
+		return 0;
+	}
+	const gap = nextElement.startTime - (element.startTime + element.duration);
+	if (gap < 0) {
+		return 0;
+	}
+	const transitionDuration = buildTransitionFromParams({
+		params: nextElement.params,
+	}).inDuration;
+	return transitionDuration > 0 ? gap + transitionDuration : 0;
+}
 
 function buildTrackNodes({
 	tracks,
@@ -46,7 +73,11 @@ function buildTrackNodes({
 	for (const track of tracks) {
 		const elements = getVisibleSortedElements({ track });
 
-		for (const element of elements) {
+		for (const [elementIndex, element] of elements.entries()) {
+			const tailHoldDuration = getTailHoldDuration({
+				elements,
+				elementIndex,
+			});
 			if (element.type === "effect") {
 				nodes.push(
 					new EffectLayerNode({
@@ -71,7 +102,8 @@ function buildTrackNodes({
 							mediaId: mediaAsset.id,
 							url: mediaAsset.url,
 							file: mediaAsset.file,
-							duration: element.duration,
+							duration: element.duration + tailHoldDuration,
+							contentDuration: element.duration,
 							timeOffset: element.startTime,
 							trimStart: element.trimStart,
 							trimEnd: element.trimEnd,
@@ -80,6 +112,7 @@ function buildTrackNodes({
 							animations: element.animations,
 							opacity: readOpacityFromParams({ params: element.params }),
 							blendMode: readBlendModeFromParams({ params: element.params }),
+							transition: buildTransitionFromParams({ params: element.params }),
 							effects: element.effects ?? [],
 							masks: element.masks ?? [],
 						}),
@@ -89,7 +122,8 @@ function buildTrackNodes({
 					nodes.push(
 						new ImageNode({
 							url: mediaAsset.url,
-							duration: element.duration,
+							duration: element.duration + tailHoldDuration,
+							contentDuration: element.duration,
 							timeOffset: element.startTime,
 							trimStart: element.trimStart,
 							trimEnd: element.trimEnd,
@@ -97,6 +131,7 @@ function buildTrackNodes({
 							animations: element.animations,
 							opacity: readOpacityFromParams({ params: element.params }),
 							blendMode: readBlendModeFromParams({ params: element.params }),
+							transition: buildTransitionFromParams({ params: element.params }),
 							effects: element.effects ?? [],
 							masks: element.masks ?? [],
 							...(isPreview && {
@@ -114,6 +149,7 @@ function buildTrackNodes({
 						transform: buildTransformFromParams({ params: element.params }),
 						opacity: readOpacityFromParams({ params: element.params }),
 						blendMode: readBlendModeFromParams({ params: element.params }),
+						transition: buildTransitionFromParams({ params: element.params }),
 						canvasCenter: { x: canvasSize.width / 2, y: canvasSize.height / 2 },
 						canvasHeight: canvasSize.height,
 						textBaseline: "middle",
@@ -136,6 +172,7 @@ function buildTrackNodes({
 						animations: element.animations,
 						opacity: readOpacityFromParams({ params: element.params }),
 						blendMode: readBlendModeFromParams({ params: element.params }),
+						transition: buildTransitionFromParams({ params: element.params }),
 						effects: element.effects ?? [],
 					}),
 				);
@@ -154,6 +191,7 @@ function buildTrackNodes({
 						animations: element.animations,
 						opacity: readOpacityFromParams({ params: element.params }),
 						blendMode: readBlendModeFromParams({ params: element.params }),
+						transition: buildTransitionFromParams({ params: element.params }),
 						effects: element.effects ?? [],
 						masks: element.masks ?? [],
 					}),
diff --git a/apps/web/src/timeline/__tests__/audio-state.test.ts b/apps/web/src/timeline/__tests__/audio-state.test.ts
new file mode 100644
index 00000000..91c422cb
--- /dev/null
+++ b/apps/web/src/timeline/__tests__/audio-state.test.ts
@@ -0,0 +1,65 @@
+import { describe, expect, test } from "bun:test";
+import {
+	dBToLinear,
+	getTrackVolume,
+	resolveEffectiveAudioGain,
+} from "@/timeline/audio-state";
+import type { AudioElement, AudioTrack } from "@/timeline";
+import { ZERO_MEDIA_TIME } from "@/wasm";
+
+function audioElement(params?: AudioElement["params"]): AudioElement {
+	return {
+		id: "audio-1",
+		name: "Audio",
+		type: "audio",
+		sourceType: "upload",
+		mediaId: "media-1",
+		duration: ZERO_MEDIA_TIME,
+		startTime: ZERO_MEDIA_TIME,
+		trimStart: ZERO_MEDIA_TIME,
+		trimEnd: ZERO_MEDIA_TIME,
+		params: params ?? { volume: 0, muted: false },
+	};
+}
+
+describe("audio state", () => {
+	test("track volume offsets element gain in decibels", () => {
+		const gain = resolveEffectiveAudioGain({
+			element: audioElement({ volume: -6, muted: false }),
+			trackVolume: -6,
+			localTime: 0,
+		});
+
+		expect(gain).toBeCloseTo(dBToLinear(-12), 6);
+	});
+	test("track volume and mute resolve to playback gain", () => {
+		const element = audioElement({ volume: 0, muted: false });
+
+		expect(
+			resolveEffectiveAudioGain({ element, trackVolume: 0, localTime: 0 }),
+		).toBe(1);
+		expect(
+			resolveEffectiveAudioGain({ element, trackVolume: -6, localTime: 0 }),
+		).toBeCloseTo(dBToLinear(-6), 6);
+		expect(
+			resolveEffectiveAudioGain({
+				element,
+				trackMuted: true,
+				trackVolume: 0,
+				localTime: 0,
+			}),
+		).toBe(0);
+	});
+
+	test("missing track volume defaults to unity", () => {
+		const track: AudioTrack = {
+			id: "track-1",
+			name: "Audio track",
+			type: "audio",
+			elements: [],
+			muted: false,
+		};
+
+		expect(getTrackVolume({ track })).toBe(0);
+	});
+});
diff --git a/apps/web/src/timeline/audio-state.ts b/apps/web/src/timeline/audio-state.ts
index 6c8f3044..34220cc9 100644
--- a/apps/web/src/timeline/audio-state.ts
+++ b/apps/web/src/timeline/audio-state.ts
@@ -1,7 +1,8 @@
 import { hasKeyframesForPath } from "@/animation/keyframe-query";
 import { resolveNumberAtTime } from "@/animation/values";
 import { VOLUME_DB_MAX, VOLUME_DB_MIN } from "./audio-constants";
-import type { TimelineElement } from "./types";
+import type { TimelineElement, TimelineTrack } from "./types";
+import { TICKS_PER_SECOND } from "@/wasm";
 const DEFAULT_STEP_SECONDS = 1 / 60;
 
 export type AudioCapableElement = Extract<
@@ -29,6 +30,13 @@ export function getElementVolume({
 	const value = element.params.volume;
 	return typeof value === "number" ? value : 0;
 }
+export function getTrackVolume({
+	track,
+}: {
+	track: Extract<TimelineTrack, { muted: boolean }>;
+}): number {
+	return typeof track.volume === "number" ? track.volume : 0;
+}
 
 export function isElementMuted({
 	element,
@@ -49,15 +57,15 @@ export function hasAnimatedVolume({
 	});
 }
 
-import { TICKS_PER_SECOND } from "@/wasm";
-
 export function resolveEffectiveAudioGain({
 	element,
 	trackMuted = false,
+	trackVolume = 0,
 	localTime,
 }: {
 	element: AudioCapableElement;
 	trackMuted?: boolean;
+	trackVolume?: number;
 	localTime: number;
 }): number {
 	if (trackMuted || isElementMuted({ element })) {
@@ -71,7 +79,7 @@ export function resolveEffectiveAudioGain({
 		localTime: Math.round(localTime * TICKS_PER_SECOND),
 	});
 
-	return dBToLinear(resolvedDb);
+	return dBToLinear(resolvedDb + trackVolume);
 }
 
 export function buildWaveformGainSamples({
@@ -91,12 +99,14 @@ export function buildWaveformGainSamples({
 export function buildAudioGainAutomation({
 	element,
 	trackMuted = false,
+	trackVolume = 0,
 	fromLocalTime,
 	toLocalTime,
 	stepSeconds = DEFAULT_STEP_SECONDS,
 }: {
 	element: AudioCapableElement;
 	trackMuted?: boolean;
+	trackVolume?: number;
 	fromLocalTime: number;
 	toLocalTime: number;
 	stepSeconds?: number;
@@ -115,6 +125,7 @@ export function buildAudioGainAutomation({
 			gain: resolveEffectiveAudioGain({
 				element,
 				trackMuted,
+				trackVolume,
 				localTime,
 			}),
 		});
@@ -126,6 +137,7 @@ export function buildAudioGainAutomation({
 			element,
 			trackMuted,
 			localTime: endTime,
+			trackVolume,
 		}),
 	});
 
diff --git a/apps/web/src/timeline/components/__tests__/drop-target-transition.test.ts b/apps/web/src/timeline/components/__tests__/drop-target-transition.test.ts
new file mode 100644
index 00000000..d3246a19
--- /dev/null
+++ b/apps/web/src/timeline/components/__tests__/drop-target-transition.test.ts
@@ -0,0 +1,221 @@
+import { describe, expect, test } from "bun:test";
+import type {
+	AudioTrack,
+	EffectTrack,
+	ImageElement,
+	SceneTracks,
+	TextTrack,
+	VideoElement,
+	VideoTrack,
+} from "@/timeline";
+import { computeTransitionCutDropTarget } from "@/timeline/components/drop-target";
+import { mediaTime, TICKS_PER_SECOND, ZERO_MEDIA_TIME } from "@/wasm";
+
+const PIXELS_PER_SECOND = 50;
+
+function buildImage({
+	id,
+	start,
+	duration,
+}: {
+	id: string;
+	start: number;
+	duration: number;
+}): ImageElement {
+	return {
+		id,
+		type: "image",
+		name: id,
+		mediaId: `media-${id}`,
+		startTime: mediaTime({ ticks: start }),
+		duration: mediaTime({ ticks: duration }),
+		trimStart: ZERO_MEDIA_TIME,
+		trimEnd: ZERO_MEDIA_TIME,
+		params: { opacity: 0.75 },
+	};
+}
+
+function buildVideo({
+	id,
+	start,
+	duration,
+}: {
+	id: string;
+	start: number;
+	duration: number;
+}): VideoElement {
+	return {
+		id,
+		type: "video",
+		name: id,
+		mediaId: `media-${id}`,
+		startTime: mediaTime({ ticks: start }),
+		duration: mediaTime({ ticks: duration }),
+		trimStart: ZERO_MEDIA_TIME,
+		trimEnd: ZERO_MEDIA_TIME,
+		params: { opacity: 1 },
+	};
+}
+
+function buildVideoTrack({
+	elements,
+}: {
+	elements: VideoTrack["elements"];
+}): VideoTrack {
+	return {
+		id: "visual",
+		type: "video",
+		name: "Visual",
+		elements,
+		muted: false,
+		hidden: false,
+	};
+}
+
+function buildTracks({
+	main,
+	overlay = [],
+	audio = [],
+}: {
+	main: VideoTrack;
+	overlay?: SceneTracks["overlay"];
+	audio?: AudioTrack[];
+}): SceneTracks {
+	return { main, overlay, audio };
+}
+
+function resolve({
+	tracks,
+	mouseX,
+	mouseY = 10,
+}: {
+	tracks: SceneTracks;
+	mouseX: number;
+	mouseY?: number;
+}) {
+	return computeTransitionCutDropTarget({
+		mouseX,
+		mouseY,
+		tracks,
+		pixelsPerSecond: PIXELS_PER_SECOND,
+		zoomLevel: 1,
+	});
+}
+
+const oneSecond = TICKS_PER_SECOND;
+
+function adjacentTrack(): VideoTrack {
+	return buildVideoTrack({
+		elements: [
+			buildImage({ id: "outgoing", start: 0, duration: oneSecond }),
+			buildVideo({ id: "incoming", start: oneSecond, duration: oneSecond }),
+		],
+	});
+}
+
+describe("computeTransitionCutDropTarget", () => {
+	test("resolves an adjacent image and video cut within 12 screen pixels", () => {
+		const target = resolve({
+			tracks: buildTracks({ main: adjacentTrack() }),
+			mouseX: 55,
+		});
+
+		expect(target).toEqual({
+			trackIndex: 0,
+			isNewTrack: false,
+			insertPosition: null,
+			xPosition: mediaTime({ ticks: oneSecond }),
+			targetElement: null,
+			targetCut: {
+				trackId: "visual",
+				outgoingElementId: "outgoing",
+				incomingElementId: "incoming",
+				time: mediaTime({ ticks: oneSecond }),
+			},
+		});
+	});
+
+	test("rejects a pointer beyond 12 screen pixels", () => {
+		expect(
+			resolve({ tracks: buildTracks({ main: adjacentTrack() }), mouseX: 63 }),
+		).toBeNull();
+	});
+
+	test("rejects gaps and overlaps", () => {
+		const incoming = buildVideo({
+			id: "incoming",
+			start: oneSecond,
+			duration: oneSecond,
+		});
+		const gap = buildVideoTrack({
+			elements: [
+				buildImage({ id: "outgoing", start: 0, duration: oneSecond - 1 }),
+				incoming,
+			],
+		});
+		const overlap = buildVideoTrack({
+			elements: [
+				buildImage({ id: "outgoing", start: 0, duration: oneSecond + 1 }),
+				incoming,
+			],
+		});
+
+		expect(
+			resolve({ tracks: buildTracks({ main: gap }), mouseX: 50 }),
+		).toBeNull();
+		expect(
+			resolve({ tracks: buildTracks({ main: overlap }), mouseX: 50 }),
+		).toBeNull();
+	});
+
+	test("rejects the first visual clip boundary", () => {
+		expect(
+			resolve({ tracks: buildTracks({ main: adjacentTrack() }), mouseX: 0 }),
+		).toBeNull();
+	});
+
+	test("rejects audio, text, and effect tracks", () => {
+		const textTrack: TextTrack = {
+			id: "text",
+			type: "text",
+			name: "Text",
+			elements: [],
+			hidden: false,
+		};
+		const effectTrack: EffectTrack = {
+			id: "effect",
+			type: "effect",
+			name: "Effect",
+			elements: [],
+			hidden: false,
+		};
+		const audioTrack: AudioTrack = {
+			id: "audio",
+			type: "audio",
+			name: "Audio",
+			elements: [],
+			muted: false,
+		};
+		const main = adjacentTrack();
+
+		expect(
+			resolve({
+				tracks: buildTracks({ main, overlay: [textTrack] }),
+				mouseX: 50,
+			}),
+		).toBeNull();
+		expect(
+			resolve({
+				tracks: buildTracks({ main, overlay: [effectTrack] }),
+				mouseX: 50,
+			}),
+		).toBeNull();
+		expect(
+			resolve({
+				tracks: buildTracks({ main, audio: [audioTrack] }),
+				mouseX: 50,
+				mouseY: 72,
+			}),
+		).toBeNull();
+	});
+});
diff --git a/apps/web/src/timeline/components/drop-target.ts b/apps/web/src/timeline/components/drop-target.ts
index f68a4b72..e22c8af9 100644
--- a/apps/web/src/timeline/components/drop-target.ts
+++ b/apps/web/src/timeline/components/drop-target.ts
@@ -1,5 +1,9 @@
-import type { TimelineTrack, TimelineElement } from "@/timeline";
-import type { ComputeDropTargetParams, DropTarget } from "@/timeline";
+import type {
+	ComputeDropTargetParams,
+	DropTarget,
+	TimelineElement,
+	TimelineTrack,
+} from "@/timeline";
 import { resolveTrackPlacement } from "@/timeline/placement";
 import { TIMELINE_TRACK_GAP_PX } from "./layout";
 import { getTrackHeight } from "./track-layout";
@@ -97,6 +101,71 @@ function fallbackNewTrackDropTarget({
 		insertPosition: null,
 		xPosition,
 		targetElement: EMPTY_TARGET_ELEMENT,
+		targetCut: null,
+	};
+}
+
+export function computeTransitionCutDropTarget({
+	mouseX,
+	mouseY,
+	tracks,
+	pixelsPerSecond,
+	zoomLevel,
+}: {
+	mouseX: number;
+	mouseY: number;
+	tracks: ComputeDropTargetParams["tracks"];
+	pixelsPerSecond: number;
+	zoomLevel: number;
+}): DropTarget | null {
+	const orderedTracks = [...tracks.overlay, tracks.main, ...tracks.audio];
+	const trackAtMouse = getTrackAtY({ mouseY, tracks: orderedTracks });
+	if (!trackAtMouse) return null;
+
+	const track = orderedTracks[trackAtMouse.trackIndex];
+	if (!track || track.type !== "video") return null;
+
+	const elements = track.elements
+		.filter((element) => element.type === "video" || element.type === "image")
+		.slice()
+		.sort((left, right) => left.startTime - right.startTime);
+	let nearest: {
+		outgoingElementId: string;
+		incomingElementId: string;
+		time: MediaTime;
+		distance: number;
+	} | null = null;
+
+	for (let index = 1; index < elements.length; index += 1) {
+		const outgoing = elements[index - 1];
+		const incoming = elements[index];
+		const cutTime = incoming.startTime;
+		if (outgoing.startTime + outgoing.duration !== cutTime) continue;
+
+		const cutX = (cutTime / TICKS_PER_SECOND) * pixelsPerSecond * zoomLevel;
+		const distance = Math.abs(mouseX - cutX);
+		if (distance > 12 || (nearest && nearest.distance <= distance)) continue;
+		nearest = {
+			outgoingElementId: outgoing.id,
+			incomingElementId: incoming.id,
+			time: cutTime,
+			distance,
+		};
+	}
+
+	if (!nearest) return null;
+	return {
+		trackIndex: trackAtMouse.trackIndex,
+		isNewTrack: false,
+		insertPosition: null,
+		xPosition: nearest.time,
+		targetElement: null,
+		targetCut: {
+			trackId: track.id,
+			outgoingElementId: nearest.outgoingElementId,
+			incomingElementId: nearest.incomingElementId,
+			time: nearest.time,
+		},
 	};
 }
 
@@ -133,7 +202,9 @@ export function computeDropTarget({
 		const placementResult = resolveTrackPlacement({
 			tracks,
 			elementType,
-			timeSpans: [{ startTime: xPosition, duration: elementDuration, excludeElementId }],
+			timeSpans: [
+				{ startTime: xPosition, duration: elementDuration, excludeElementId },
+			],
 			strategy: {
 				type: "preferIndex",
 				trackIndex: 0,
@@ -153,6 +224,7 @@ export function computeDropTarget({
 			insertPosition: emptyTimelineResult.insertPosition,
 			xPosition,
 			targetElement: EMPTY_TARGET_ELEMENT,
+			targetCut: null,
 		};
 	}
 
@@ -168,7 +240,9 @@ export function computeDropTarget({
 		const placementResult = resolveTrackPlacement({
 			tracks,
 			elementType,
-			timeSpans: [{ startTime: xPosition, duration: elementDuration, excludeElementId }],
+			timeSpans: [
+				{ startTime: xPosition, duration: elementDuration, excludeElementId },
+			],
 			strategy: {
 				type: "preferIndex",
 				trackIndex: isAboveAllTracks ? 0 : orderedTracks.length - 1,
@@ -188,6 +262,7 @@ export function computeDropTarget({
 			insertPosition: outOfBoundsResult.insertPosition,
 			xPosition,
 			targetElement: EMPTY_TARGET_ELEMENT,
+			targetCut: null,
 		};
 	}
 
@@ -210,6 +285,7 @@ export function computeDropTarget({
 				insertPosition: null,
 				xPosition,
 				targetElement,
+				targetCut: null,
 			};
 		}
 	}
@@ -218,7 +294,9 @@ export function computeDropTarget({
 	const placementResult = resolveTrackPlacement({
 		tracks,
 		elementType,
-		timeSpans: [{ startTime: xPosition, duration: elementDuration, excludeElementId }],
+		timeSpans: [
+			{ startTime: xPosition, duration: elementDuration, excludeElementId },
+		],
 		strategy: {
 			type: "preferIndex",
 			trackIndex,
@@ -242,6 +320,7 @@ export function computeDropTarget({
 			insertPosition: null,
 			xPosition: adjustedXPosition,
 			targetElement: EMPTY_TARGET_ELEMENT,
+			targetCut: null,
 		};
 	}
 
@@ -251,6 +330,7 @@ export function computeDropTarget({
 		insertPosition: placementResult.insertPosition,
 		xPosition,
 		targetElement: EMPTY_TARGET_ELEMENT,
+		targetCut: null,
 	};
 }
 
diff --git a/apps/web/src/timeline/components/index.tsx b/apps/web/src/timeline/components/index.tsx
index 8edbb6fc..527f6d8d 100644
--- a/apps/web/src/timeline/components/index.tsx
+++ b/apps/web/src/timeline/components/index.tsx
@@ -53,6 +53,8 @@ import {
 	getTimelineZoomMin,
 	getTimelinePaddingPx,
 } from "@/timeline";
+import { doesElementHaveEnabledAudio } from "@/timeline/audio-separation";
+import type { MediaAsset } from "@/media/types";
 import { timelineTimeToPixels } from "@/timeline/pixel-utils";
 import {
 	getTrackHeight,
@@ -84,9 +86,11 @@ import { useEditor } from "@/editor/use-editor";
 import { useScrollPosition } from "@/timeline/hooks/use-scroll-position";
 import { useTimelinePlayhead } from "@/timeline/hooks/use-timeline-playhead";
 import { DragLine } from "./drag-line";
+import { TIMELINE_LAYERS } from "./layers";
 import { invokeAction } from "@/actions";
 import { resolveTimelineElementIntersections } from "./selection-hit-testing";
 import { cn } from "@/utils/ui";
+import { usePropertiesStore } from "@/components/editor/panels/properties/stores/properties-store";
 
 const TRACKS_CONTAINER_MAX_HEIGHT = 800;
 const FALLBACK_CONTAINER_WIDTH = 1000;
@@ -302,12 +306,12 @@ export function Timeline() {
 
 	const { dragView, handleElementMouseDown, handleElementClick } =
 		useElementInteraction({
-		zoomLevel,
-		tracksContainerRef,
-		tracksScrollRef,
-		snappingEnabled,
-		onSnapPointChange: handleSnapPointChange,
-	});
+			zoomLevel,
+			tracksContainerRef,
+			tracksScrollRef,
+			snappingEnabled,
+			onSnapPointChange: handleSnapPointChange,
+		});
 	const isElementDragging = dragView.kind === "dragging";
 
 	const {
@@ -455,13 +459,13 @@ export function Timeline() {
 					className="relative isolate flex flex-1 flex-col overflow-hidden"
 					ref={tracksContainerRef}
 				>
-					<SelectionBox
-						bounds={selectionBox?.bounds ?? null}
-					/>
+					<SelectionBox bounds={selectionBox?.bounds ?? null} />
 					<DragLine
 						dropTarget={dropTarget}
 						tracks={tracks}
-						isVisible={isDragOver && !dropTarget?.targetElement}
+						isVisible={
+							isDragOver && !dropTarget?.targetElement && !dropTarget?.targetCut
+						}
 						headerHeight={timelineHeaderHeight}
 					/>
 					<DragLine
@@ -612,6 +616,8 @@ function TrackLabelsPanel({
 }) {
 	const editor = useEditor();
 	const scene = useEditor((e) => e.scenes.getActiveSceneOrNull());
+	const mediaAssets = useEditor((e) => e.media.getAssets());
+	const selectTrack = usePropertiesStore((state) => state.selectTrack);
 	const tracks = useMemo<TimelineTrack[]>(
 		() =>
 			scene
@@ -619,7 +625,7 @@ function TrackLabelsPanel({
 				: [],
 		[scene],
 	);
-	const { selectedElements } = useElementSelection();
+	const { selectedElements, clearElementSelection } = useElementSelection();
 	const tracksWithSelection = useMemo(
 		() => new Set(selectedElements.map((el) => el.trackId)),
 		[selectedElements],
@@ -653,6 +659,7 @@ function TrackLabelsPanel({
 							{tracks.map((track, index) => {
 								const expandedRows = trackExpandedRowsMap[index];
 								const baseHeight = getTrackHeight({ type: track.type });
+								const hasAudio = trackContainsAudio({ track, mediaAssets });
 
 								return (
 									<div
@@ -667,21 +674,16 @@ function TrackLabelsPanel({
 										}}
 									>
 										<div
-											className="flex shrink-0 items-center justify-end gap-2 px-3"
+											className="flex shrink-0 items-center justify-end gap-1.5 px-2"
 											style={{ height: `${baseHeight}px` }}
 										>
-											{canTrackHaveAudio(track) && (
-												<TrackToggleIcon
-													isOff={track.muted}
-													icons={{
-														on: VolumeHighIcon,
-														off: VolumeOffIcon,
+											{hasAudio && canTrackHaveAudio(track) && (
+												<TrackAudioButton
+													track={track}
+													onClick={() => {
+														clearElementSelection();
+														selectTrack({ trackId: track.id });
 													}}
-													onClick={() =>
-														editor.timeline.toggleTrackMute({
-															trackId: track.id,
-														})
-													}
 												/>
 											)}
 											{canTrackBeHidden(track) && (
@@ -780,8 +782,8 @@ function TimelineTrackRows({
 	const draggingElementIds = useMemo(
 		() =>
 			dragView.kind === "dragging"
-			? dragView.memberTimeOffsets
-			: (null as ReadonlyMap<string, MediaTime> | null),
+				? dragView.memberTimeOffsets
+				: (null as ReadonlyMap<string, MediaTime> | null),
 		[dragView],
 	);
 	const sortedTracks = useMemo(() => {
@@ -833,6 +835,18 @@ function TimelineTrackRows({
 										: null
 								}
 							/>
+							{isDragOver && dropTarget?.targetCut?.trackId === track.id && (
+								<div
+									className="bg-primary pointer-events-none absolute inset-y-0 w-0.5 -translate-x-1/2 shadow-[0_0_8px_var(--primary)]"
+									style={{
+										left: timelineTimeToPixels({
+											time: dropTarget.targetCut.time,
+											zoomLevel,
+										}),
+										zIndex: TIMELINE_LAYERS.dragLine,
+									}}
+								/>
+							)}
 						</div>
 					</ContextMenuTrigger>
 					<ContextMenuContent className="w-40">
@@ -915,24 +929,72 @@ function TrackToggleIcon({
 	};
 	onClick: () => void;
 }) {
+	const icon = isOff ? icons.off : icons.on;
 	return (
-		<>
-			{isOff ? (
-				<HugeiconsIcon
-					icon={icons.off}
-					className="text-destructive size-4 cursor-pointer"
-					onClick={onClick}
-				/>
-			) : (
-				<HugeiconsIcon
-					icon={icons.on}
-					className="text-muted-foreground size-4 cursor-pointer"
-					onClick={onClick}
-				/>
+		<button
+			type="button"
+			className={cn(
+				"flex size-6 items-center justify-center rounded-sm hover:bg-accent",
+				isOff ? "text-destructive" : "text-muted-foreground",
 			)}
-		</>
+			onClick={onClick}
+		>
+			<HugeiconsIcon icon={icon} className="size-4" />
+		</button>
 	);
 }
+function TrackAudioButton({
+	track,
+	onClick,
+}: {
+	track: Extract<TimelineTrack, { muted: boolean }>;
+	onClick: () => void;
+}) {
+	return (
+		<button
+			type="button"
+			className={cn(
+				"flex size-6 items-center justify-center rounded-sm hover:bg-accent",
+				track.muted ? "text-destructive" : "text-muted-foreground",
+			)}
+			aria-label={`Edit ${track.name} audio`}
+			onClick={onClick}
+		>
+			<HugeiconsIcon
+				icon={track.muted ? VolumeOffIcon : VolumeHighIcon}
+				className="size-4"
+			/>
+		</button>
+	);
+}
+
+function trackContainsAudio({
+	track,
+	mediaAssets,
+}: {
+	track: TimelineTrack;
+	mediaAssets: MediaAsset[];
+}): boolean {
+	if (!canTrackHaveAudio(track)) {
+		return false;
+	}
+
+	for (const element of track.elements) {
+		if (element.type === "audio") {
+			return true;
+		}
+		if (element.type !== "video") {
+			continue;
+		}
+		const mediaAsset = mediaAssets.find(
+			(asset) => asset.id === element.mediaId,
+		);
+		if (doesElementHaveEnabledAudio({ element, mediaAsset })) {
+			return true;
+		}
+	}
+	return false;
+}
 
 function PropertyTree({ rows }: { rows: ExpandedRow[] }) {
 	return (
diff --git a/apps/web/src/timeline/components/timeline-toolbar.tsx b/apps/web/src/timeline/components/timeline-toolbar.tsx
index 47906931..ba9a99fa 100644
--- a/apps/web/src/timeline/components/timeline-toolbar.tsx
+++ b/apps/web/src/timeline/components/timeline-toolbar.tsx
@@ -43,17 +43,13 @@ import {
 	Layers01Icon,
 	Chart03Icon,
 	Unlink02Icon,
-	MicIcon,
-	StopIcon,
 } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { OcRippleIcon } from "@/components/icons";
 import { GraphEditorPopover } from "./graph-editor/popover";
 import { PopoverTrigger } from "@/components/ui/popover";
 import { useGraphEditorController } from "./graph-editor/use-controller";
-import { formatElapsedSeconds } from "@/voiceover/recorder";
-import { useRecordingElapsedSeconds } from "@/voiceover/use-recording-elapsed";
-import { useVoiceOverStore } from "@/voiceover/voiceover-store";
+import { VoiceOverRecorderPopover } from "@/voiceover/voiceover-popover";
 
 export function TimelineToolbar({
 	zoomLevel,
@@ -100,10 +96,6 @@ function ToolbarLeftSection() {
 	const isCurrentlyBookmarked = useEditor((e) =>
 		e.scenes.isBookmarked({ time: e.playback.getCurrentTime() }),
 	);
-	const isRecordingVoiceOver = useVoiceOverStore(
-		(state) => state.status === "recording",
-	);
-	const voiceOverElapsedSeconds = useRecordingElapsedSeconds();
 	const canFreezeFrame = useEditor((e) => {
 		const time = e.playback.getCurrentTime();
 		const { overlay, main } = e.scenes.getActiveScene().tracks;
@@ -211,22 +203,7 @@ function ToolbarLeftSection() {
 					onClick={({ event }) => handleAction({ action: "freeze-frame", event })}
 				/>
 
-				<ToolbarButton
-					icon={
-						<HugeiconsIcon icon={isRecordingVoiceOver ? StopIcon : MicIcon} />
-					}
-					tooltip={
-						isRecordingVoiceOver ? "Stop voice-over" : "Record voice-over"
-					}
-					isActive={isRecordingVoiceOver}
-					onClick={({ event }) => handleAction({ action: "voice-over", event })}
-				/>
-
-				{isRecordingVoiceOver && (
-					<span className="text-destructive min-w-9 text-center text-xs tabular-nums">
-						{formatElapsedSeconds({ seconds: voiceOverElapsedSeconds })}
-					</span>
-				)}
+				<VoiceOverRecorderPopover />
 
 				<ToolbarButton
 					icon={<HugeiconsIcon icon={Delete02Icon} />}
diff --git a/apps/web/src/timeline/controllers/__tests__/drag-drop-controller-transition.test.ts b/apps/web/src/timeline/controllers/__tests__/drag-drop-controller-transition.test.ts
new file mode 100644
index 00000000..b24f9ad9
--- /dev/null
+++ b/apps/web/src/timeline/controllers/__tests__/drag-drop-controller-transition.test.ts
@@ -0,0 +1,190 @@
+import { describe, expect, mock, test } from "bun:test";
+import type { DragEvent } from "react";
+import type { SceneTracks, VideoElement, VideoTrack } from "@/timeline";
+import {
+	DragDropController,
+	type DragDropConfig,
+	type DragDropConfigRef,
+} from "@/timeline/controllers/drag-drop-controller";
+import { TimelineDragSource } from "@/timeline/drag-source";
+import { mediaTime, TICKS_PER_SECOND, ZERO_MEDIA_TIME } from "@/wasm";
+
+function buildVideo({
+	id,
+	start,
+}: {
+	id: string;
+	start: number;
+}): VideoElement {
+	return {
+		id,
+		type: "video",
+		name: id,
+		mediaId: `media-${id}`,
+		startTime: mediaTime({ ticks: start }),
+		duration: mediaTime({ ticks: TICKS_PER_SECOND }),
+		trimStart: ZERO_MEDIA_TIME,
+		trimEnd: ZERO_MEDIA_TIME,
+		params: { opacity: id === "incoming" ? 0.8 : 1 },
+	};
+}
+
+function buildTracks(): SceneTracks {
+	const main: VideoTrack = {
+		id: "visual",
+		type: "video",
+		name: "Visual",
+		elements: [
+			buildVideo({ id: "outgoing", start: 0 }),
+			buildVideo({ id: "incoming", start: TICKS_PER_SECOND }),
+		],
+		muted: false,
+		hidden: false,
+	};
+	return { overlay: [], main, audio: [] };
+}
+
+function buildDataTransfer(): DataTransfer {
+	return {
+		types: [],
+		files: [],
+		dropEffect: "none",
+		effectAllowed: "none",
+		setData: mock(() => {}),
+	} as unknown as DataTransfer;
+}
+
+function buildDragEvent({
+	clientX,
+	dataTransfer,
+}: {
+	clientX: number;
+	dataTransfer: DataTransfer;
+}): DragEvent {
+	return {
+		clientX,
+		clientY: 10,
+		dataTransfer,
+		preventDefault: mock(() => {}),
+	} as unknown as DragEvent;
+}
+
+function setup() {
+	const dragSource = new TimelineDragSource();
+	const updateElements = mock<DragDropConfig["updateElements"]>(() => {});
+	const insertElement = mock<DragDropConfig["insertElement"]>(() => {});
+	const executeCommand = mock<DragDropConfig["executeCommand"]>(() => {});
+	const tracksElement = {
+		scrollLeft: 0,
+		scrollTop: 0,
+		getBoundingClientRect: () => ({ left: 0, top: 0 }),
+	} as unknown as HTMLDivElement;
+	const config: DragDropConfig = {
+		zoomLevel: 1,
+		getContainerEl: () => tracksElement,
+		getHeaderEl: () => null,
+		getTracksScrollEl: () => tracksElement,
+		getActiveProjectFps: () => null,
+		getActiveProjectId: () => null,
+		getSceneTracks: buildTracks,
+		getCurrentPlayheadTime: () => ZERO_MEDIA_TIME,
+		getMediaAssets: () => [],
+		dragSource,
+		addMediaAsset: () => Promise.resolve(null),
+		executeCommand,
+		insertElement,
+		updateElements,
+		addClipEffect: mock(() => {}),
+	};
+	const configRef: DragDropConfigRef = { current: config };
+	return {
+		controller: new DragDropController({ configRef }),
+		dragSource,
+		updateElements,
+		insertElement,
+		executeCommand,
+	};
+}
+
+function beginTransitionDrag(
+	dragSource: TimelineDragSource,
+	dataTransfer: DataTransfer,
+) {
+	dragSource.begin({
+		dataTransfer,
+		dragData: {
+			type: "transition",
+			id: "push-left",
+			name: "Slide left",
+			transitionKind: "push-left",
+			inDuration: 0.45,
+			outDuration: 0,
+		},
+	});
+}
+
+describe("DragDropController transition drops", () => {
+	test("hovers and applies a transition only to the incoming clip", () => {
+		const {
+			controller,
+			dragSource,
+			updateElements,
+			insertElement,
+			executeCommand,
+		} = setup();
+		const dataTransfer = buildDataTransfer();
+		beginTransitionDrag(dragSource, dataTransfer);
+
+		controller.onDragOver(buildDragEvent({ clientX: 50, dataTransfer }));
+
+		expect(dataTransfer.dropEffect).toBe("copy");
+		expect(controller.dropTarget?.targetCut).toEqual({
+			trackId: "visual",
+			outgoingElementId: "outgoing",
+			incomingElementId: "incoming",
+			time: mediaTime({ ticks: TICKS_PER_SECOND }),
+		});
+
+		controller.onDrop(buildDragEvent({ clientX: 50, dataTransfer }));
+
+		expect(updateElements).toHaveBeenCalledTimes(1);
+		expect(updateElements).toHaveBeenCalledWith({
+			updates: [
+				{
+					trackId: "visual",
+					elementId: "incoming",
+					patch: {
+						params: {
+							opacity: 0.8,
+							"transition.kind": "push-left",
+							"transition.inDuration": 0.45,
+							"transition.outDuration": 0,
+						},
+					},
+				},
+			],
+		});
+		expect(insertElement).not.toHaveBeenCalled();
+		expect(executeCommand).not.toHaveBeenCalled();
+	});
+
+	test("does nothing when the transition has no cut target", () => {
+		const {
+			controller,
+			dragSource,
+			updateElements,
+			insertElement,
+			executeCommand,
+		} = setup();
+		const dataTransfer = buildDataTransfer();
+		beginTransitionDrag(dragSource, dataTransfer);
+
+		controller.onDragOver(buildDragEvent({ clientX: 80, dataTransfer }));
+		expect(controller.dropTarget).toBeNull();
+		controller.onDrop(buildDragEvent({ clientX: 80, dataTransfer }));
+
+		expect(updateElements).not.toHaveBeenCalled();
+		expect(insertElement).not.toHaveBeenCalled();
+		expect(executeCommand).not.toHaveBeenCalled();
+	});
+});
diff --git a/apps/web/src/timeline/controllers/drag-drop-controller.ts b/apps/web/src/timeline/controllers/drag-drop-controller.ts
index a419101f..6b4c8bbf 100644
--- a/apps/web/src/timeline/controllers/drag-drop-controller.ts
+++ b/apps/web/src/timeline/controllers/drag-drop-controller.ts
@@ -17,7 +17,10 @@ import {
 import { AddTrackCommand, InsertElementCommand } from "@/commands/timeline";
 import { BatchCommand } from "@/commands";
 import type { Command } from "@/commands/base-command";
-import { computeDropTarget } from "@/timeline/components/drop-target";
+import {
+	computeDropTarget,
+	computeTransitionCutDropTarget,
+} from "@/timeline/components/drop-target";
 import type { TimelineDragSource } from "@/timeline/drag-source";
 import type {
 	TrackType,
@@ -26,11 +29,13 @@ import type {
 	SceneTracks,
 	TimelineTrack,
 	CreateTimelineElement,
+	TimelineElement,
 } from "@/timeline";
 import type { TimelineDragData } from "@/timeline/drag";
 import type { MediaAsset } from "@/media/types";
 import type { ProcessedMediaAsset } from "@/media/processing";
 import { roundFrameTime, type MediaTime } from "@/wasm";
+import { withVisualTransitionParams } from "@/rendering/transition";
 
 // --- Config ---
 
@@ -54,6 +59,14 @@ export interface DragDropConfig {
 		placement: { mode: "explicit"; trackId: string };
 		element: CreateTimelineElement;
 	}) => void;
+	updateElements: (args: {
+		updates: Array<{
+			trackId: string;
+			elementId: string;
+			patch: Partial<TimelineElement>;
+		}>;
+		pushHistory?: boolean;
+	}) => void;
 	addClipEffect: (args: {
 		trackId: string;
 		elementId: string;
@@ -85,7 +98,7 @@ interface TimelineCoords {
 function elementTypeFromDrag({
 	dragData,
 }: {
-	dragData: TimelineDragData;
+	dragData: Exclude<TimelineDragData, { type: "transition" }>;
 }): ElementType {
 	switch (dragData.type) {
 		case "text":
@@ -104,7 +117,7 @@ function elementTypeFromDrag({
 function getTargetElementTypesForDrag({
 	dragData,
 }: {
-	dragData: TimelineDragData;
+	dragData: Exclude<TimelineDragData, { type: "transition" }>;
 }): string[] | undefined {
 	if (dragData.type === "effect") return dragData.targetElementTypes;
 	if (dragData.type === "media") return dragData.targetElementTypes;
@@ -115,7 +128,7 @@ function getDurationForDrag({
 	dragData,
 	mediaAssets,
 }: {
-	dragData: TimelineDragData;
+	dragData: Exclude<TimelineDragData, { type: "transition" }>;
 	mediaAssets: MediaAsset[];
 }): MediaTime {
 	if (dragData.type !== "media") return DEFAULT_NEW_ELEMENT_DURATION;
@@ -202,6 +215,18 @@ export class DragDropController {
 			}
 			return;
 		}
+		if (dragData.type === "transition") {
+			const target = computeTransitionCutDropTarget({
+				mouseX: coords.mouseX,
+				mouseY: coords.mouseY,
+				tracks: this.config.getSceneTracks(),
+				pixelsPerSecond: BASE_TIMELINE_PIXELS_PER_SECOND,
+				zoomLevel: this.config.zoomLevel,
+			});
+			this.setOver({ dropTarget: target, elementType: null });
+			if (target) event.dataTransfer.dropEffect = "copy";
+			return;
+		}
 
 		const elementType = elementTypeFromDrag({ dragData });
 		const duration = getDurationForDrag({
@@ -374,9 +399,47 @@ export class DragDropController {
 			case "media":
 				this.executeMediaDrop({ target, dragData });
 				return;
+			case "transition":
+				this.executeTransitionDrop({ target, dragData });
+				return;
 		}
 	}
 
+	private executeTransitionDrop({
+		target,
+		dragData,
+	}: {
+		target: DropTarget;
+		dragData: Extract<TimelineDragData, { type: "transition" }>;
+	}): void {
+		const cut = target.targetCut;
+		if (!cut) return;
+
+		const tracks = orderedTracks({ sceneTracks: this.config.getSceneTracks() });
+		const track = tracks.find(({ id }) => id === cut.trackId);
+		const incoming = track?.elements.find(
+			({ id }) => id === cut.incomingElementId,
+		);
+		if (!incoming) return;
+
+		this.config.updateElements({
+			updates: [
+				{
+					trackId: cut.trackId,
+					elementId: cut.incomingElementId,
+					patch: {
+						params: withVisualTransitionParams({
+							params: incoming.params,
+							transitionKind: dragData.transitionKind,
+							inDuration: dragData.inDuration,
+							outDuration: dragData.outDuration,
+						}),
+					},
+				},
+			],
+		});
+	}
+
 	private executeTextDrop({
 		target,
 		dragData,
diff --git a/apps/web/src/timeline/defaults.ts b/apps/web/src/timeline/defaults.ts
index d32fb649..bc679ab9 100644
--- a/apps/web/src/timeline/defaults.ts
+++ b/apps/web/src/timeline/defaults.ts
@@ -14,6 +14,9 @@ const defaultTransform: Transform = {
 const defaultOpacity = 1;
 const defaultBlendMode: BlendMode = "normal";
 const defaultVolume = 0;
+const defaultTransitionKind = "fade";
+const defaultTransitionDuration = 0;
+const defaultTrackVolume = 0;
 
 const defaultTextLetterSpacing = 0;
 const defaultTextLineHeight = 1.2;
@@ -60,6 +63,9 @@ const defaultTextElement: Omit<TextElement, "id"> = {
 		"transform.rotate": defaultTransform.rotate,
 		opacity: defaultOpacity,
 		blendMode: defaultBlendMode,
+		"transition.kind": defaultTransitionKind,
+		"transition.inDuration": defaultTransitionDuration,
+		"transition.outDuration": defaultTransitionDuration,
 	},
 };
 
@@ -75,6 +81,9 @@ export const DEFAULTS = {
 		opacity: defaultOpacity,
 		blendMode: defaultBlendMode,
 		volume: defaultVolume,
+		transitionKind: defaultTransitionKind,
+		transitionDuration: defaultTransitionDuration,
+		trackVolume: defaultTrackVolume,
 	},
 	text: {
 		letterSpacing: defaultTextLetterSpacing,
diff --git a/apps/web/src/timeline/drag.ts b/apps/web/src/timeline/drag.ts
index 7bf99a6d..06f721da 100644
--- a/apps/web/src/timeline/drag.ts
+++ b/apps/web/src/timeline/drag.ts
@@ -1,42 +1,50 @@
-import type { MaskableElement, VisualElement } from "./types";
-import type { ParamValues } from "@/params";
-
-interface BaseDragData {
-	id: string;
-	name: string;
-}
-
-export interface MediaDragData extends BaseDragData {
-	type: "media";
-	mediaType: "image" | "video" | "audio";
-	targetElementTypes?: MaskableElement["type"][];
-}
-
-export interface TextDragData extends BaseDragData {
-	type: "text";
-	content: string;
-}
-
-export interface StickerDragData extends BaseDragData {
-	type: "sticker";
-	stickerId: string;
-}
-
-export interface GraphicDragData extends BaseDragData {
-	type: "graphic";
-	definitionId: string;
-	params: Partial<ParamValues>;
-}
-
-export interface EffectDragData extends BaseDragData {
-	type: "effect";
-	effectType: string;
-	targetElementTypes: VisualElement["type"][];
-}
-
-export type TimelineDragData =
-	| MediaDragData
-	| TextDragData
-	| StickerDragData
-	| GraphicDragData
-	| EffectDragData;
+import type { MaskableElement, VisualElement } from "./types";
+import type { ParamValues } from "@/params";
+import type { TransitionKind } from "@/rendering/transition";
+
+interface BaseDragData {
+	id: string;
+	name: string;
+}
+
+export interface MediaDragData extends BaseDragData {
+	type: "media";
+	mediaType: "image" | "video" | "audio";
+	targetElementTypes?: MaskableElement["type"][];
+}
+
+export interface TextDragData extends BaseDragData {
+	type: "text";
+	content: string;
+}
+
+export interface StickerDragData extends BaseDragData {
+	type: "sticker";
+	stickerId: string;
+}
+
+export interface GraphicDragData extends BaseDragData {
+	type: "graphic";
+	definitionId: string;
+	params: Partial<ParamValues>;
+}
+
+export interface EffectDragData extends BaseDragData {
+	type: "effect";
+	effectType: string;
+	targetElementTypes: VisualElement["type"][];
+}
+export interface TransitionDragData extends BaseDragData {
+	type: "transition";
+	transitionKind: TransitionKind;
+	inDuration: number;
+	outDuration: number;
+}
+
+export type TimelineDragData =
+	| MediaDragData
+	| TextDragData
+	| StickerDragData
+	| GraphicDragData
+	| EffectDragData
+	| TransitionDragData;
diff --git a/apps/web/src/timeline/hooks/use-timeline-drag-drop.ts b/apps/web/src/timeline/hooks/use-timeline-drag-drop.ts
index c405819e..cde3874f 100644
--- a/apps/web/src/timeline/hooks/use-timeline-drag-drop.ts
+++ b/apps/web/src/timeline/hooks/use-timeline-drag-drop.ts
@@ -36,6 +36,7 @@ export function useTimelineDragDrop({
 		addMediaAsset: (args) => editor.media.addMediaAsset(args),
 		executeCommand: (command) => editor.command.execute({ command }),
 		insertElement: (args) => editor.timeline.insertElement(args),
+		updateElements: (args) => editor.timeline.updateElements(args),
 		addClipEffect: (args) => editor.timeline.addClipEffect(args),
 	};
 	const configRef = useCommittedRef(config);
diff --git a/apps/web/src/timeline/placement/track-factory.ts b/apps/web/src/timeline/placement/track-factory.ts
index 9c69ea8c..290141fc 100644
--- a/apps/web/src/timeline/placement/track-factory.ts
+++ b/apps/web/src/timeline/placement/track-factory.ts
@@ -84,6 +84,7 @@ export function buildEmptyTrack({
 				elements: [],
 				hidden: false,
 				muted: false,
+				volume: 0,
 			};
 		case "text":
 			return {
@@ -108,6 +109,7 @@ export function buildEmptyTrack({
 				type: "audio",
 				elements: [],
 				muted: false,
+				volume: 0,
 			};
 		case "effect":
 			return {
diff --git a/apps/web/src/timeline/scenes.ts b/apps/web/src/timeline/scenes.ts
index 8aa1b6b5..155bda96 100644
--- a/apps/web/src/timeline/scenes.ts
+++ b/apps/web/src/timeline/scenes.ts
@@ -1,114 +1,115 @@
-import type { TScene } from "@/timeline";
-import { generateUUID } from "@/utils/id";
-import { calculateTotalDuration } from "@/timeline";
-import { MAIN_TRACK_NAME } from "@/timeline/placement/main-track";
-import { type MediaTime, ZERO_MEDIA_TIME } from "@/wasm";
-
-export function getMainScene({ scenes }: { scenes: TScene[] }): TScene | null {
-	return scenes.find((scene) => scene.isMain) || null;
-}
-
-export function ensureMainScene({ scenes }: { scenes: TScene[] }): TScene[] {
-	const hasMain = scenes.some((scene) => scene.isMain);
-	if (!hasMain) {
-		const mainScene = buildDefaultScene({ name: "Main scene", isMain: true });
-		return [mainScene, ...scenes];
-	}
-	return scenes;
-}
-
-export function buildDefaultScene({
-	name,
-	isMain,
-}: {
-	name: string;
-	isMain: boolean;
-}): TScene {
-	return {
-		id: generateUUID(),
-		name,
-		isMain,
-		tracks: {
-			overlay: [],
-			main: {
-				id: generateUUID(),
-				name: MAIN_TRACK_NAME,
-				type: "video",
-				elements: [],
-				muted: false,
-				hidden: false,
-			},
-			audio: [],
-		},
-		bookmarks: [],
-		createdAt: new Date(),
-		updatedAt: new Date(),
-	};
-}
-
-export function canDeleteScene({ scene }: { scene: TScene }): {
-	canDelete: boolean;
-	reason?: string;
-} {
-	if (scene.isMain) {
-		return { canDelete: false, reason: "Cannot delete main scene" };
-	}
-	return { canDelete: true };
-}
-
-export function getFallbackSceneAfterDelete({
-	scenes,
-	deletedSceneId,
-	currentSceneId,
-}: {
-	scenes: TScene[];
-	deletedSceneId: string;
-	currentSceneId: string | null;
-}): TScene | null {
-	if (currentSceneId !== deletedSceneId) {
-		return scenes.find((s) => s.id === currentSceneId) || null;
-	}
-	return getMainScene({ scenes });
-}
-
-export function findCurrentScene({
-	scenes,
-	currentSceneId,
-}: {
-	scenes: TScene[];
-	currentSceneId: string;
-}): TScene | null {
-	return (
-		scenes.find((s) => s.id === currentSceneId) ||
-		getMainScene({ scenes }) ||
-		scenes[0] ||
-		null
-	);
-}
-
-export function getProjectDurationFromScenes({
-	scenes,
-}: {
-	scenes: TScene[];
-}): MediaTime {
-	const mainScene = getMainScene({ scenes }) ?? scenes[0] ?? null;
-	if (!mainScene?.tracks) {
-		return ZERO_MEDIA_TIME;
-	}
-
-	return calculateTotalDuration({ tracks: mainScene.tracks });
-}
-
-export function updateSceneInArray({
-	scenes,
-	sceneId,
-	updates,
-}: {
-	scenes: TScene[];
-	sceneId: string;
-	updates: Partial<TScene>;
-}): TScene[] {
-	return scenes.map((scene) =>
-		scene.id === sceneId ? { ...scene, ...updates } : scene,
-	);
-}
+import type { TScene } from "@/timeline";
+import { generateUUID } from "@/utils/id";
+import { calculateTotalDuration } from "@/timeline";
+import { MAIN_TRACK_NAME } from "@/timeline/placement/main-track";
+import { type MediaTime, ZERO_MEDIA_TIME } from "@/wasm";
+
+export function getMainScene({ scenes }: { scenes: TScene[] }): TScene | null {
+	return scenes.find((scene) => scene.isMain) || null;
+}
+
+export function ensureMainScene({ scenes }: { scenes: TScene[] }): TScene[] {
+	const hasMain = scenes.some((scene) => scene.isMain);
+	if (!hasMain) {
+		const mainScene = buildDefaultScene({ name: "Main scene", isMain: true });
+		return [mainScene, ...scenes];
+	}
+	return scenes;
+}
+
+export function buildDefaultScene({
+	name,
+	isMain,
+}: {
+	name: string;
+	isMain: boolean;
+}): TScene {
+	return {
+		id: generateUUID(),
+		name,
+		isMain,
+		tracks: {
+			overlay: [],
+			main: {
+				id: generateUUID(),
+				name: MAIN_TRACK_NAME,
+				type: "video",
+				elements: [],
+				muted: false,
+				volume: 0,
+				hidden: false,
+			},
+			audio: [],
+		},
+		bookmarks: [],
+		createdAt: new Date(),
+		updatedAt: new Date(),
+	};
+}
+
+export function canDeleteScene({ scene }: { scene: TScene }): {
+	canDelete: boolean;
+	reason?: string;
+} {
+	if (scene.isMain) {
+		return { canDelete: false, reason: "Cannot delete main scene" };
+	}
+	return { canDelete: true };
+}
+
+export function getFallbackSceneAfterDelete({
+	scenes,
+	deletedSceneId,
+	currentSceneId,
+}: {
+	scenes: TScene[];
+	deletedSceneId: string;
+	currentSceneId: string | null;
+}): TScene | null {
+	if (currentSceneId !== deletedSceneId) {
+		return scenes.find((s) => s.id === currentSceneId) || null;
+	}
+	return getMainScene({ scenes });
+}
+
+export function findCurrentScene({
+	scenes,
+	currentSceneId,
+}: {
+	scenes: TScene[];
+	currentSceneId: string;
+}): TScene | null {
+	return (
+		scenes.find((s) => s.id === currentSceneId) ||
+		getMainScene({ scenes }) ||
+		scenes[0] ||
+		null
+	);
+}
+
+export function getProjectDurationFromScenes({
+	scenes,
+}: {
+	scenes: TScene[];
+}): MediaTime {
+	const mainScene = getMainScene({ scenes }) ?? scenes[0] ?? null;
+	if (!mainScene?.tracks) {
+		return ZERO_MEDIA_TIME;
+	}
+
+	return calculateTotalDuration({ tracks: mainScene.tracks });
+}
+
+export function updateSceneInArray({
+	scenes,
+	sceneId,
+	updates,
+}: {
+	scenes: TScene[];
+	sceneId: string;
+	updates: Partial<TScene>;
+}): TScene[] {
+	return scenes.map((scene) =>
+		scene.id === sceneId ? { ...scene, ...updates } : scene,
+	);
+}
diff --git a/apps/web/src/timeline/types.ts b/apps/web/src/timeline/types.ts
index 5b3e4d29..48f3f592 100644
--- a/apps/web/src/timeline/types.ts
+++ b/apps/web/src/timeline/types.ts
@@ -37,6 +37,7 @@ export interface VideoTrack extends BaseTrack {
 	type: "video";
 	elements: (VideoElement | ImageElement)[];
 	muted: boolean;
+	volume?: number;
 	hidden: boolean;
 }
 
@@ -50,6 +51,7 @@ export interface AudioTrack extends BaseTrack {
 	type: "audio";
 	elements: AudioElement[];
 	muted: boolean;
+	volume?: number;
 }
 
 export interface GraphicTrack extends BaseTrack {
@@ -256,12 +258,20 @@ export type ElementDragView =
 			readonly dropTarget: DropTarget | null;
 	  };
 
+export interface TransitionCutTarget {
+	trackId: string;
+	outgoingElementId: string;
+	incomingElementId: string;
+	time: MediaTime;
+}
+
 export interface DropTarget {
 	trackIndex: number;
 	isNewTrack: boolean;
 	insertPosition: "above" | "below" | null;
 	xPosition: MediaTime;
 	targetElement: { elementId: string; trackId: string } | null;
+	targetCut: TransitionCutTarget | null;
 }
 
 export interface ComputeDropTargetParams {
diff --git a/apps/web/src/voiceover/__tests__/devices.test.ts b/apps/web/src/voiceover/__tests__/devices.test.ts
new file mode 100644
index 00000000..524e8c3f
--- /dev/null
+++ b/apps/web/src/voiceover/__tests__/devices.test.ts
@@ -0,0 +1,72 @@
+import { describe, expect, test } from "bun:test";
+import {
+	DEFAULT_AUDIO_INPUT_DEVICE_ID,
+	buildVoiceOverAudioConstraints,
+	normalizeSelectedDeviceId,
+	type VoiceOverInputDevice,
+} from "@/voiceover/devices";
+
+const devices: VoiceOverInputDevice[] = [
+	{
+		deviceId: DEFAULT_AUDIO_INPUT_DEVICE_ID,
+		label: "System default microphone",
+		isDefault: true,
+	},
+	{
+		deviceId: "blue-yeti-snowball",
+		label: "Blue Snowball",
+		isDefault: false,
+	},
+];
+
+describe("buildVoiceOverAudioConstraints", () => {
+	test("uses default processing constraints without an exact device", () => {
+		const constraints = buildVoiceOverAudioConstraints({ deviceId: null });
+		expect(constraints.audio).toEqual({
+			echoCancellation: true,
+			noiseSuppression: true,
+			autoGainControl: true,
+		});
+	});
+
+	test("adds an exact device constraint for a selected microphone", () => {
+		const constraints = buildVoiceOverAudioConstraints({
+			deviceId: "blue-yeti-snowball",
+		});
+		expect(constraints.audio).toEqual({
+			deviceId: { exact: "blue-yeti-snowball" },
+			echoCancellation: true,
+			noiseSuppression: true,
+			autoGainControl: true,
+		});
+	});
+});
+
+describe("normalizeSelectedDeviceId", () => {
+	test("keeps the selected device when it is still present", () => {
+		expect(
+			normalizeSelectedDeviceId({
+				deviceId: "blue-yeti-snowball",
+				devices,
+			}),
+		).toBe("blue-yeti-snowball");
+	});
+
+	test("clears a selected device when it is no longer present", () => {
+		expect(
+			normalizeSelectedDeviceId({
+				deviceId: "missing",
+				devices,
+			}),
+		).toBeNull();
+	});
+
+	test("keeps the browser default device id", () => {
+		expect(
+			normalizeSelectedDeviceId({
+				deviceId: DEFAULT_AUDIO_INPUT_DEVICE_ID,
+				devices: [],
+			}),
+		).toBe(DEFAULT_AUDIO_INPUT_DEVICE_ID);
+	});
+});
diff --git a/apps/web/src/voiceover/__tests__/enhancements.test.ts b/apps/web/src/voiceover/__tests__/enhancements.test.ts
new file mode 100644
index 00000000..bc5b4b7c
--- /dev/null
+++ b/apps/web/src/voiceover/__tests__/enhancements.test.ts
@@ -0,0 +1,133 @@
+import { describe, expect, test } from "bun:test";
+import {
+	DEFAULT_VOICE_OVER_ENHANCEMENTS,
+	encodeAudioBufferToWav,
+	getAudioBufferPeak,
+	hasEnabledVoiceOverEnhancement,
+	type VoiceOverEnhancementSettings,
+} from "@/voiceover/enhancements";
+
+/* eslint-disable opencut/prefer-object-params -- Browser AudioBuffer methods are positional. */
+class FakeAudioBuffer implements AudioBuffer {
+	duration: number;
+	length: number;
+	numberOfChannels: number;
+	sampleRate: number;
+
+	constructor(
+		private readonly channels: Array<Float32Array<ArrayBuffer>>,
+		sampleRate: number,
+	) {
+		this.length = channels[0]?.length ?? 0;
+		this.numberOfChannels = channels.length;
+		this.sampleRate = sampleRate;
+		this.duration = this.length / sampleRate;
+	}
+
+	copyFromChannel(
+		destination: Float32Array<ArrayBuffer>,
+		channelNumber: number,
+		bufferOffset = 0,
+	): void {
+		destination.set(
+			this.getChannelData(channelNumber).slice(
+				bufferOffset,
+				bufferOffset + destination.length,
+			),
+		);
+	}
+
+	copyToChannel(
+		source: Float32Array<ArrayBuffer>,
+		channelNumber: number,
+		bufferOffset = 0,
+	): void {
+		this.getChannelData(channelNumber).set(source, bufferOffset);
+	}
+
+	getChannelData(channel: number): Float32Array<ArrayBuffer> {
+		const data = this.channels[channel];
+		if (!data) {
+			throw new Error(`Missing channel ${channel}`);
+		}
+		return data;
+	}
+}
+/* eslint-enable opencut/prefer-object-params */
+
+describe("hasEnabledVoiceOverEnhancement", () => {
+	test("detects enabled defaults", () => {
+		expect(
+			hasEnabledVoiceOverEnhancement({
+				settings: DEFAULT_VOICE_OVER_ENHANCEMENTS,
+			}),
+		).toBe(true);
+	});
+
+	test("detects an all-disabled chain", () => {
+		const settings: VoiceOverEnhancementSettings = {
+			voiceBoost: false,
+			noiseGate: false,
+			highPass: false,
+			deEss: false,
+			limiter: false,
+			normalize: false,
+		};
+		expect(hasEnabledVoiceOverEnhancement({ settings })).toBe(false);
+	});
+});
+
+describe("getAudioBufferPeak", () => {
+	test("returns the maximum absolute sample", () => {
+		const buffer = new FakeAudioBuffer(
+			[
+				createSamples([0, -0.25, 0.5]),
+				createSamples([0.1, -0.8, 0.2]),
+			],
+			48000,
+		);
+
+		expect(getAudioBufferPeak({ buffer })).toBeCloseTo(0.8);
+	});
+});
+
+describe("encodeAudioBufferToWav", () => {
+	test("writes a 16-bit PCM WAV header", async () => {
+		const buffer = new FakeAudioBuffer(
+			[createSamples([0, 0.5, -0.5])],
+			44100,
+		);
+
+		const blob = encodeAudioBufferToWav({ buffer });
+		const view = new DataView(await blob.arrayBuffer());
+
+		expect(blob.type).toBe("audio/wav");
+		expect(blob.size).toBe(50);
+		expect(readAscii({ view, offset: 0, length: 4 })).toBe("RIFF");
+		expect(readAscii({ view, offset: 8, length: 4 })).toBe("WAVE");
+		expect(view.getUint16(22, true)).toBe(1);
+		expect(view.getUint32(24, true)).toBe(44100);
+		expect(view.getUint16(34, true)).toBe(16);
+		expect(readAscii({ view, offset: 36, length: 4 })).toBe("data");
+	});
+});
+
+function readAscii({
+	view,
+	offset,
+	length,
+}: {
+	view: DataView;
+	offset: number;
+	length: number;
+}): string {
+	return Array.from({ length }, (_, index) =>
+		String.fromCharCode(view.getUint8(offset + index)),
+	).join("");
+}
+
+function createSamples(values: number[]): Float32Array<ArrayBuffer> {
+	const samples = new Float32Array(new ArrayBuffer(values.length * 4));
+	samples.set(values);
+	return samples;
+}
diff --git a/apps/web/src/voiceover/devices.ts b/apps/web/src/voiceover/devices.ts
new file mode 100644
index 00000000..dd5b680c
--- /dev/null
+++ b/apps/web/src/voiceover/devices.ts
@@ -0,0 +1,93 @@
+"use client";
+
+export const DEFAULT_AUDIO_INPUT_DEVICE_ID = "default";
+
+export interface VoiceOverInputDevice {
+	deviceId: string;
+	label: string;
+	isDefault: boolean;
+}
+
+export function buildVoiceOverAudioConstraints({
+	deviceId,
+}: {
+	deviceId?: string | null;
+}): MediaStreamConstraints {
+	const audio: MediaTrackConstraints = {
+		echoCancellation: true,
+		noiseSuppression: true,
+		autoGainControl: true,
+	};
+
+	if (deviceId && deviceId !== DEFAULT_AUDIO_INPUT_DEVICE_ID) {
+		audio.deviceId = { exact: deviceId };
+	}
+
+	return { audio };
+}
+
+export function normalizeSelectedDeviceId({
+	deviceId,
+	devices,
+}: {
+	deviceId: string | null;
+	devices: VoiceOverInputDevice[];
+}): string | null {
+	if (!deviceId) {
+		return null;
+	}
+
+	if (deviceId === DEFAULT_AUDIO_INPUT_DEVICE_ID) {
+		return deviceId;
+	}
+
+	return devices.some((device) => device.deviceId === deviceId)
+		? deviceId
+		: null;
+}
+
+export async function listVoiceOverInputDevices({
+	requestPermission = false,
+}: {
+	requestPermission?: boolean;
+} = {}): Promise<VoiceOverInputDevice[]> {
+	const mediaDevices = navigator.mediaDevices;
+	if (!mediaDevices?.enumerateDevices) {
+		throw new Error("Microphone selection is not supported in this browser");
+	}
+
+	let permissionStream: MediaStream | null = null;
+	if (requestPermission) {
+		permissionStream = await mediaDevices.getUserMedia({
+			audio: {
+				echoCancellation: true,
+				noiseSuppression: true,
+				autoGainControl: true,
+			},
+		});
+	}
+
+	try {
+		const devices = await mediaDevices.enumerateDevices();
+		let inputIndex = 1;
+		return devices
+			.filter((device) => device.kind === "audioinput")
+			.map((device) => {
+				const isDefault = device.deviceId === DEFAULT_AUDIO_INPUT_DEVICE_ID;
+				const fallbackLabel = isDefault
+					? "System default microphone"
+					: `Microphone ${inputIndex++}`;
+				return {
+					deviceId: device.deviceId,
+					label: device.label || fallbackLabel,
+					isDefault,
+				};
+			});
+	} finally {
+		if (permissionStream) {
+			for (const track of permissionStream.getTracks()) {
+				track.stop();
+			}
+		}
+	}
+}
diff --git a/apps/web/src/voiceover/enhancements.ts b/apps/web/src/voiceover/enhancements.ts
new file mode 100644
index 00000000..8718406f
--- /dev/null
+++ b/apps/web/src/voiceover/enhancements.ts
@@ -0,0 +1,321 @@
+"use client";
+
+export interface VoiceOverEnhancementSettings {
+	voiceBoost: boolean;
+	noiseGate: boolean;
+	highPass: boolean;
+	deEss: boolean;
+	limiter: boolean;
+	normalize: boolean;
+}
+
+export const DEFAULT_VOICE_OVER_ENHANCEMENTS: VoiceOverEnhancementSettings = {
+	voiceBoost: true,
+	noiseGate: true,
+	highPass: true,
+	deEss: false,
+	limiter: true,
+	normalize: true,
+};
+
+export const VOICE_OVER_ENHANCEMENT_LABELS: Record<
+	keyof VoiceOverEnhancementSettings,
+	{ label: string; description: string }
+> = {
+	voiceBoost: {
+		label: "Voice boost",
+		description: "Adds compression and presence for a stronger voice.",
+	},
+	noiseGate: {
+		label: "Noise gate",
+		description: "Turns down quiet room noise between phrases.",
+	},
+	highPass: {
+		label: "High-pass",
+		description: "Removes low rumble and desk vibration.",
+	},
+	deEss: {
+		label: "De-ess",
+		description: "Softens harsh S sounds and upper fizz.",
+	},
+	limiter: {
+		label: "Limiter",
+		description: "Catches peaks after boosts.",
+	},
+	normalize: {
+		label: "Normalize",
+		description: "Raises the finished take to a consistent level.",
+	},
+};
+
+const WAV_BITS_PER_SAMPLE = 16;
+const WAV_HEADER_BYTES = 44;
+const TARGET_PEAK = 0.92;
+const NOISE_GATE_THRESHOLD = 0.018;
+const NOISE_GATE_FLOOR = 0.18;
+
+export function hasEnabledVoiceOverEnhancement({
+	settings,
+}: {
+	settings: VoiceOverEnhancementSettings;
+}): boolean {
+	return Object.values(settings).some(Boolean);
+}
+
+export async function applyVoiceOverEnhancementsToBlob({
+	blob,
+	settings,
+}: {
+	blob: Blob;
+	settings: VoiceOverEnhancementSettings;
+}): Promise<Blob> {
+	if (!hasEnabledVoiceOverEnhancement({ settings })) {
+		return blob;
+	}
+
+	const audioContext = createAudioContext();
+	try {
+		const buffer = await audioContext.decodeAudioData(await blob.arrayBuffer());
+		const renderedBuffer = await renderEnhancedVoiceOverBuffer({
+			buffer,
+			settings,
+		});
+		return encodeAudioBufferToWav({ buffer: renderedBuffer });
+	} finally {
+		void audioContext.close();
+	}
+}
+
+export async function renderEnhancedVoiceOverBuffer({
+	buffer,
+	settings,
+}: {
+	buffer: AudioBuffer;
+	settings: VoiceOverEnhancementSettings;
+}): Promise<AudioBuffer> {
+	const offlineContext = new OfflineAudioContext(
+		buffer.numberOfChannels,
+		Math.max(1, buffer.length),
+		buffer.sampleRate,
+	);
+	const source = offlineContext.createBufferSource();
+	source.buffer = settings.noiseGate
+		? applyNoiseGateToBuffer({
+				buffer,
+				context: offlineContext,
+				threshold: NOISE_GATE_THRESHOLD,
+				floor: NOISE_GATE_FLOOR,
+			})
+		: buffer;
+
+	let current: AudioNode = source;
+
+	if (settings.highPass) {
+		const highPass = offlineContext.createBiquadFilter();
+		highPass.type = "highpass";
+		highPass.frequency.value = 85;
+		highPass.Q.value = 0.7;
+		current.connect(highPass);
+		current = highPass;
+	}
+
+	if (settings.voiceBoost) {
+		const presence = offlineContext.createBiquadFilter();
+		presence.type = "peaking";
+		presence.frequency.value = 3200;
+		presence.Q.value = 0.9;
+		presence.gain.value = 2.5;
+
+		const compressor = offlineContext.createDynamicsCompressor();
+		compressor.threshold.value = -24;
+		compressor.knee.value = 12;
+		compressor.ratio.value = 3.5;
+		compressor.attack.value = 0.004;
+		compressor.release.value = 0.16;
+
+		const makeupGain = offlineContext.createGain();
+		makeupGain.gain.value = 1.45;
+
+		current.connect(presence);
+		presence.connect(compressor);
+		compressor.connect(makeupGain);
+		current = makeupGain;
+	}
+
+	if (settings.deEss) {
+		const deEss = offlineContext.createBiquadFilter();
+		deEss.type = "peaking";
+		deEss.frequency.value = 6400;
+		deEss.Q.value = 2.2;
+		deEss.gain.value = -3;
+		current.connect(deEss);
+		current = deEss;
+	}
+
+	if (settings.limiter) {
+		const limiter = offlineContext.createDynamicsCompressor();
+		limiter.threshold.value = -1;
+		limiter.knee.value = 0;
+		limiter.ratio.value = 20;
+		limiter.attack.value = 0.001;
+		limiter.release.value = 0.1;
+		current.connect(limiter);
+		current = limiter;
+	}
+
+	current.connect(offlineContext.destination);
+	source.start(0);
+
+	const rendered = await offlineContext.startRendering();
+	if (settings.normalize) {
+		normalizeAudioBufferPeak({ buffer: rendered, targetPeak: TARGET_PEAK });
+	}
+	clampAudioBuffer({ buffer: rendered, maxPeak: 0.98 });
+	return rendered;
+}
+
+export function encodeAudioBufferToWav({
+	buffer,
+}: {
+	buffer: AudioBuffer;
+}): Blob {
+	const numChannels = buffer.numberOfChannels;
+	const bytesPerSample = WAV_BITS_PER_SAMPLE / 8;
+	const dataSize = buffer.length * numChannels * bytesPerSample;
+	const arrayBuffer = new ArrayBuffer(WAV_HEADER_BYTES + dataSize);
+	const view = new DataView(arrayBuffer);
+
+	writeAsciiString({ view, offset: 0, value: "RIFF" });
+	view.setUint32(4, 36 + dataSize, true);
+	writeAsciiString({ view, offset: 8, value: "WAVE" });
+	writeAsciiString({ view, offset: 12, value: "fmt " });
+	view.setUint32(16, 16, true);
+	view.setUint16(20, 1, true);
+	view.setUint16(22, numChannels, true);
+	view.setUint32(24, buffer.sampleRate, true);
+	view.setUint32(28, buffer.sampleRate * numChannels * bytesPerSample, true);
+	view.setUint16(32, numChannels * bytesPerSample, true);
+	view.setUint16(34, WAV_BITS_PER_SAMPLE, true);
+	writeAsciiString({ view, offset: 36, value: "data" });
+	view.setUint32(40, dataSize, true);
+
+	let offset = WAV_HEADER_BYTES;
+	for (let sampleIndex = 0; sampleIndex < buffer.length; sampleIndex++) {
+		for (let channel = 0; channel < numChannels; channel++) {
+			const sample = Math.max(
+				-1,
+				Math.min(1, buffer.getChannelData(channel)[sampleIndex] ?? 0),
+			);
+			const int16 = sample < 0 ? sample * 0x8000 : sample * 0x7fff;
+			view.setInt16(offset, int16, true);
+			offset += bytesPerSample;
+		}
+	}
+
+	return new Blob([arrayBuffer], { type: "audio/wav" });
+}
+
+export function getAudioBufferPeak({ buffer }: { buffer: AudioBuffer }): number {
+	let peak = 0;
+	for (let channel = 0; channel < buffer.numberOfChannels; channel++) {
+		const channelData = buffer.getChannelData(channel);
+		for (let index = 0; index < channelData.length; index++) {
+			peak = Math.max(peak, Math.abs(channelData[index] ?? 0));
+		}
+	}
+	return peak;
+}
+
+function normalizeAudioBufferPeak({
+	buffer,
+	targetPeak,
+}: {
+	buffer: AudioBuffer;
+	targetPeak: number;
+}): void {
+	const peak = getAudioBufferPeak({ buffer });
+	if (peak <= 0 || peak >= targetPeak) {
+		return;
+	}
+
+	const gain = targetPeak / peak;
+	for (let channel = 0; channel < buffer.numberOfChannels; channel++) {
+		const channelData = buffer.getChannelData(channel);
+		for (let index = 0; index < channelData.length; index++) {
+			channelData[index] *= gain;
+		}
+	}
+}
+
+function clampAudioBuffer({
+	buffer,
+	maxPeak,
+}: {
+	buffer: AudioBuffer;
+	maxPeak: number;
+}): void {
+	for (let channel = 0; channel < buffer.numberOfChannels; channel++) {
+		const channelData = buffer.getChannelData(channel);
+		for (let index = 0; index < channelData.length; index++) {
+			channelData[index] = Math.max(
+				-maxPeak,
+				Math.min(maxPeak, channelData[index] ?? 0),
+			);
+		}
+	}
+}
+
+function applyNoiseGateToBuffer({
+	buffer,
+	context,
+	threshold,
+	floor,
+}: {
+	buffer: AudioBuffer;
+	context: OfflineAudioContext;
+	threshold: number;
+	floor: number;
+}): AudioBuffer {
+	const gated = context.createBuffer(
+		buffer.numberOfChannels,
+		buffer.length,
+		buffer.sampleRate,
+	);
+
+	for (let channel = 0; channel < buffer.numberOfChannels; channel++) {
+		const input = buffer.getChannelData(channel);
+		const output = gated.getChannelData(channel);
+		for (let index = 0; index < input.length; index++) {
+			const sample = input[index] ?? 0;
+			output[index] =
+				Math.abs(sample) < threshold
+					? sample * floor
+					: sample;
+		}
+	}
+
+	return gated;
+}
+
+function createAudioContext(): AudioContext {
+	const AudioContextConstructor =
+		window.AudioContext ||
+		(window as typeof window & { webkitAudioContext?: typeof AudioContext })
+			.webkitAudioContext;
+
+	return new AudioContextConstructor();
+}
+
+function writeAsciiString({
+	view,
+	offset,
+	value,
+}: {
+	view: DataView;
+	offset: number;
+	value: string;
+}): void {
+	for (let index = 0; index < value.length; index++) {
+		view.setUint8(offset + index, value.charCodeAt(index));
+	}
+}
diff --git a/apps/web/src/voiceover/live-waveform.tsx b/apps/web/src/voiceover/live-waveform.tsx
new file mode 100644
index 00000000..cd25c833
--- /dev/null
+++ b/apps/web/src/voiceover/live-waveform.tsx
@@ -0,0 +1,171 @@
+"use client";
+
+import { useEffect, useRef, useState } from "react";
+import { cn } from "@/utils/ui";
+import { getActiveVoiceOverRecordingStream } from "@/voiceover/recorder";
+
+const FFT_SIZE = 1024;
+const HISTORY_SIZE = 96;
+
+export function VoiceOverLiveWaveform({
+	recording,
+	className,
+}: {
+	recording: boolean;
+	className?: string;
+}) {
+	const canvasRef = useRef<HTMLCanvasElement>(null);
+	const levelRef = useRef(0);
+	const historyRef = useRef<number[]>(
+		Array.from({ length: HISTORY_SIZE }, () => 0),
+	);
+	const [level, setLevel] = useState(0);
+
+	useEffect(() => {
+		const canvas = canvasRef.current;
+		if (!canvas || !recording) {
+			drawWaveform({
+				canvas,
+				history: historyRef.current,
+				level: 0,
+			});
+			setLevel(0);
+			return;
+		}
+
+		const stream = getActiveVoiceOverRecordingStream();
+		if (!stream) {
+			return;
+		}
+
+		const audioContext = createAudioContext();
+		const source = audioContext.createMediaStreamSource(stream);
+		const analyser = audioContext.createAnalyser();
+		analyser.fftSize = FFT_SIZE;
+		analyser.smoothingTimeConstant = 0.72;
+		source.connect(analyser);
+
+		const samples = new Uint8Array(analyser.fftSize);
+		let animationFrame = 0;
+		let lastLevelUpdate = 0;
+
+		const render = (timestamp: number) => {
+			analyser.getByteTimeDomainData(samples);
+			const rms = getRmsLevel({ samples });
+			levelRef.current = rms;
+			historyRef.current = [...historyRef.current.slice(1), rms];
+			drawWaveform({
+				canvas,
+				history: historyRef.current,
+				level: rms,
+			});
+
+			if (timestamp - lastLevelUpdate > 80) {
+				lastLevelUpdate = timestamp;
+				setLevel(rms);
+			}
+			animationFrame = requestAnimationFrame(render);
+		};
+
+		animationFrame = requestAnimationFrame(render);
+
+		return () => {
+			cancelAnimationFrame(animationFrame);
+			source.disconnect();
+			analyser.disconnect();
+			void audioContext.close();
+		};
+	}, [recording]);
+
+	return (
+		<div className={cn("space-y-2", className)}>
+			<div className="bg-muted relative h-16 overflow-hidden rounded-sm border">
+				<canvas ref={canvasRef} className="absolute inset-0 size-full" />
+			</div>
+			<div className="bg-muted h-1.5 overflow-hidden rounded-full">
+				<div
+					className="bg-primary h-full rounded-full transition-[width]"
+					style={{ width: `${Math.min(100, Math.round(level * 140))}%` }}
+				/>
+			</div>
+		</div>
+	);
+}
+
+function getRmsLevel({ samples }: { samples: Uint8Array }): number {
+	let sum = 0;
+	for (let index = 0; index < samples.length; index++) {
+		const centered = ((samples[index] ?? 128) - 128) / 128;
+		sum += centered * centered;
+	}
+	return Math.sqrt(sum / samples.length);
+}
+
+function drawWaveform({
+	canvas,
+	history,
+	level,
+}: {
+	canvas: HTMLCanvasElement | null;
+	history: number[];
+	level: number;
+}): void {
+	if (!canvas) {
+		return;
+	}
+
+	const rect = canvas.getBoundingClientRect();
+	const dpr = window.devicePixelRatio || 1;
+	const width = Math.max(1, Math.round(rect.width * dpr));
+	const height = Math.max(1, Math.round(rect.height * dpr));
+	if (canvas.width !== width || canvas.height !== height) {
+		canvas.width = width;
+		canvas.height = height;
+	}
+
+	const ctx = canvas.getContext("2d");
+	if (!ctx) {
+		return;
+	}
+
+	ctx.setTransform(1, 0, 0, 1, 0, 0);
+	ctx.clearRect(0, 0, width, height);
+
+	const centerY = height / 2;
+	const step = width / Math.max(1, history.length);
+
+	ctx.strokeStyle = "rgba(148, 163, 184, 0.35)";
+	ctx.lineWidth = 1;
+	ctx.beginPath();
+	ctx.moveTo(0, centerY);
+	ctx.lineTo(width, centerY);
+	ctx.stroke();
+
+	for (let index = 0; index < history.length; index++) {
+		const value = Math.max(0, history[index] ?? 0);
+		const barHeight = Math.max(1, Math.min(height, value * height * 2.8));
+		const x = Math.round(index * step);
+		const y = Math.round(centerY - barHeight / 2);
+		ctx.fillStyle =
+			value > 0.62
+				? "rgba(239, 68, 68, 0.9)"
+				: value > 0.32
+					? "rgba(245, 158, 11, 0.9)"
+					: "rgba(34, 197, 94, 0.9)";
+		ctx.fillRect(x, y, Math.max(1, Math.floor(step - 1)), barHeight);
+	}
+
+	if (level > 0.78) {
+		ctx.fillStyle = "rgba(239, 68, 68, 0.18)";
+		ctx.fillRect(0, 0, width, height);
+	}
+}
+
+function createAudioContext(): AudioContext {
+	const AudioContextConstructor =
+		window.AudioContext ||
+		(window as typeof window & { webkitAudioContext?: typeof AudioContext })
+			.webkitAudioContext;
+
+	return new AudioContextConstructor();
+}
diff --git a/apps/web/src/voiceover/recorder.ts b/apps/web/src/voiceover/recorder.ts
index b71ca74f..48322898 100644
--- a/apps/web/src/voiceover/recorder.ts
+++ b/apps/web/src/voiceover/recorder.ts
@@ -5,6 +5,8 @@
  * actual microphone stream.
  */
 
+import { buildVoiceOverAudioConstraints } from "@/voiceover/devices";
+
 export const PREFERRED_MIME_TYPES = [
 	"audio/webm;codecs=opus",
 	"audio/webm",
@@ -95,6 +97,11 @@ interface ActiveRecording {
 	startedAtMs: number;
 }
 
+export interface VoiceOverRecordingSession {
+	stream: MediaStream;
+	mimeType: string;
+}
+
 let activeRecording: ActiveRecording | null = null;
 
 function stopStreamTracks({ stream }: { stream: MediaStream }): void {
@@ -103,7 +110,15 @@ function stopStreamTracks({ stream }: { stream: MediaStream }): void {
 	}
 }
 
-export async function startVoiceOverRecording(): Promise<void> {
+export function getActiveVoiceOverRecordingStream(): MediaStream | null {
+	return activeRecording?.stream ?? null;
+}
+
+export async function startVoiceOverRecording({
+	deviceId,
+}: {
+	deviceId?: string | null;
+} = {}): Promise<VoiceOverRecordingSession> {
 	if (activeRecording) {
 		throw new Error("A voice-over recording is already in progress");
 	}
@@ -113,7 +128,24 @@ export async function startVoiceOverRecording(): Promise<void> {
 		throw new Error("Voice-over recording is not supported in this browser");
 	}
 
-	const stream = await mediaDevices.getUserMedia({ audio: true });
+	let stream: MediaStream;
+	try {
+		stream = await mediaDevices.getUserMedia(
+			buildVoiceOverAudioConstraints({ deviceId }),
+		);
+	} catch (error) {
+		if (
+			deviceId &&
+			error instanceof DOMException &&
+			(error.name === "NotFoundError" || error.name === "OverconstrainedError")
+		) {
+			stream = await mediaDevices.getUserMedia(
+				buildVoiceOverAudioConstraints({ deviceId: null }),
+			);
+		} else {
+			throw error;
+		}
+	}
 	try {
 		const mimeType = pickSupportedMimeType({
 			isTypeSupported: (candidate) => MediaRecorder.isTypeSupported(candidate),
@@ -135,6 +167,10 @@ export async function startVoiceOverRecording(): Promise<void> {
 			mimeType: recorder.mimeType || mimeType || "audio/webm",
 			startedAtMs: performance.now(),
 		};
+		return {
+			stream,
+			mimeType: activeRecording.mimeType,
+		};
 	} catch (error) {
 		stopStreamTracks({ stream });
 		throw error;
diff --git a/apps/web/src/voiceover/voiceover-popover.tsx b/apps/web/src/voiceover/voiceover-popover.tsx
new file mode 100644
index 00000000..a1f74646
--- /dev/null
+++ b/apps/web/src/voiceover/voiceover-popover.tsx
@@ -0,0 +1,276 @@
+"use client";
+
+import { useCallback, useMemo, useState } from "react";
+import { MicIcon, StopIcon } from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { RefreshCw } from "lucide-react";
+import { toast } from "sonner";
+import { invokeAction } from "@/actions";
+import { Button } from "@/components/ui/button";
+import {
+	Popover,
+	PopoverContent,
+	PopoverTrigger,
+} from "@/components/ui/popover";
+import {
+	Select,
+	SelectContent,
+	SelectItem,
+	SelectTrigger,
+	SelectValue,
+} from "@/components/ui/select";
+import { Switch } from "@/components/ui/switch";
+import {
+	Tooltip,
+	TooltipContent,
+	TooltipProvider,
+	TooltipTrigger,
+} from "@/components/ui/tooltip";
+import { cn } from "@/utils/ui";
+import {
+	DEFAULT_AUDIO_INPUT_DEVICE_ID,
+	listVoiceOverInputDevices,
+	normalizeSelectedDeviceId,
+	type VoiceOverInputDevice,
+} from "@/voiceover/devices";
+import {
+	VOICE_OVER_ENHANCEMENT_LABELS,
+	type VoiceOverEnhancementSettings,
+} from "@/voiceover/enhancements";
+import { VoiceOverLiveWaveform } from "@/voiceover/live-waveform";
+import {
+	formatElapsedSeconds,
+	getVoiceOverErrorMessage,
+} from "@/voiceover/recorder";
+import { useRecordingElapsedSeconds } from "@/voiceover/use-recording-elapsed";
+import {
+	useVoiceOverPreferencesStore,
+	useVoiceOverStore,
+} from "@/voiceover/voiceover-store";
+
+const ENHANCEMENT_ORDER: Array<keyof VoiceOverEnhancementSettings> = [
+	"voiceBoost",
+	"noiseGate",
+	"highPass",
+	"deEss",
+	"limiter",
+	"normalize",
+];
+
+export function VoiceOverRecorderPopover() {
+	const [open, setOpen] = useState(false);
+	const [devices, setDevices] = useState<VoiceOverInputDevice[]>([]);
+	const [isLoadingDevices, setIsLoadingDevices] = useState(false);
+	const status = useVoiceOverStore((state) => state.status);
+	const isRecording = status === "recording";
+	const isProcessing = status === "processing";
+	const elapsedSeconds = useRecordingElapsedSeconds();
+	const selectedDeviceId = useVoiceOverPreferencesStore(
+		(state) => state.selectedDeviceId,
+	);
+	const enhancements = useVoiceOverPreferencesStore(
+		(state) => state.enhancements,
+	);
+	const setSelectedDeviceId = useVoiceOverPreferencesStore(
+		(state) => state.setSelectedDeviceId,
+	);
+	const setEnhancementEnabled = useVoiceOverPreferencesStore(
+		(state) => state.setEnhancementEnabled,
+	);
+
+	const devicesWithDefault = useMemo(() => {
+		if (
+			devices.some(
+				(device) => device.deviceId === DEFAULT_AUDIO_INPUT_DEVICE_ID,
+			)
+		) {
+			return devices;
+		}
+		return [
+			{
+				deviceId: DEFAULT_AUDIO_INPUT_DEVICE_ID,
+				label: "System default microphone",
+				isDefault: true,
+			},
+			...devices,
+		];
+	}, [devices]);
+
+	const selectedValue = selectedDeviceId ?? DEFAULT_AUDIO_INPUT_DEVICE_ID;
+
+	const refreshDevices = useCallback(
+		async ({ requestPermission }: { requestPermission: boolean }) => {
+			setIsLoadingDevices(true);
+			try {
+				const nextDevices = await listVoiceOverInputDevices({
+					requestPermission,
+				});
+				setDevices(nextDevices);
+				const normalizedDeviceId = normalizeSelectedDeviceId({
+					deviceId: selectedDeviceId,
+					devices: nextDevices,
+				});
+				if (normalizedDeviceId !== selectedDeviceId) {
+					setSelectedDeviceId({ deviceId: normalizedDeviceId });
+				}
+			} catch (error) {
+				toast.error(getVoiceOverErrorMessage({ error }));
+			} finally {
+				setIsLoadingDevices(false);
+			}
+		},
+		[selectedDeviceId, setSelectedDeviceId],
+	);
+
+	const handleOpenChange = useCallback(
+		(nextOpen: boolean) => {
+			setOpen(nextOpen);
+			if (nextOpen) {
+				void refreshDevices({ requestPermission: true });
+			}
+		},
+		[refreshDevices],
+	);
+
+	const handleRecordClick = (event: React.MouseEvent) => {
+		event.stopPropagation();
+		void invokeAction("voice-over");
+	};
+
+	return (
+		<Popover open={open} onOpenChange={handleOpenChange}>
+			<TooltipProvider delayDuration={500}>
+				<Tooltip delayDuration={200}>
+					<TooltipTrigger asChild>
+						<PopoverTrigger asChild>
+							<Button
+								variant={isRecording ? "secondary" : "text"}
+								size="icon"
+								disabled={isProcessing}
+								className="rounded-sm"
+								onClick={(event) => event.stopPropagation()}
+							>
+								<HugeiconsIcon icon={isRecording ? StopIcon : MicIcon} />
+							</Button>
+						</PopoverTrigger>
+					</TooltipTrigger>
+					<TooltipContent>
+						{isProcessing
+							? "Saving voice-over"
+							: isRecording
+								? "Stop voice-over"
+								: "Record voice-over"}
+					</TooltipContent>
+				</Tooltip>
+			</TooltipProvider>
+
+			<PopoverContent
+				align="start"
+				className="w-80 p-3"
+				onClick={(event) => event.stopPropagation()}
+			>
+				<div className="space-y-3">
+					<div className="flex items-center justify-between gap-3">
+						<div className="min-w-0">
+							<div className="text-sm font-medium">Voice-over</div>
+							<div className="text-muted-foreground text-xs tabular-nums">
+								{isRecording
+									? formatElapsedSeconds({ seconds: elapsedSeconds })
+									: isProcessing
+										? "Saving"
+										: "Ready"}
+							</div>
+						</div>
+						<Button
+							variant={isRecording ? "secondary" : "default"}
+							size="sm"
+							disabled={isProcessing}
+							onClick={handleRecordClick}
+							className={cn(
+								"gap-1.5 rounded-sm",
+								isRecording ? "text-destructive" : "",
+							)}
+						>
+							<HugeiconsIcon
+								icon={isRecording ? StopIcon : MicIcon}
+								className="size-4"
+							/>
+							{isProcessing ? "Saving" : isRecording ? "Stop" : "Record"}
+						</Button>
+					</div>
+
+					<VoiceOverLiveWaveform recording={isRecording} />
+
+					<div className="space-y-1.5">
+						<div className="flex items-center justify-between gap-2">
+							<div className="text-muted-foreground text-xs font-medium">
+								Input
+							</div>
+							<Button
+								variant="text"
+								size="icon"
+								disabled={isLoadingDevices || isRecording}
+								onClick={() => refreshDevices({ requestPermission: true })}
+								className="size-6 rounded-sm"
+							>
+								<RefreshCw className="size-3.5" />
+							</Button>
+						</div>
+						<Select
+							value={selectedValue}
+							disabled={isRecording}
+							onValueChange={(value) =>
+								setSelectedDeviceId({
+									deviceId:
+										value === DEFAULT_AUDIO_INPUT_DEVICE_ID ? null : value,
+								})
+							}
+						>
+							<SelectTrigger className="w-full" variant="outline" size="sm">
+								<SelectValue placeholder="System default microphone" />
+							</SelectTrigger>
+							<SelectContent>
+								{devicesWithDefault.map((device) => (
+									<SelectItem key={device.deviceId} value={device.deviceId}>
+										{device.label}
+									</SelectItem>
+								))}
+							</SelectContent>
+						</Select>
+					</div>
+
+					<div className="border-border border-t pt-3">
+						<div className="text-muted-foreground mb-2 text-xs font-medium">
+							Enhancements
+						</div>
+						<div className="space-y-2">
+							{ENHANCEMENT_ORDER.map((id) => {
+								const option = VOICE_OVER_ENHANCEMENT_LABELS[id];
+								return (
+									<div
+										key={id}
+										className="flex items-start justify-between gap-3"
+									>
+										<span className="min-w-0">
+											<span className="block text-sm">{option.label}</span>
+											<span className="text-muted-foreground block text-xs leading-snug">
+												{option.description}
+											</span>
+										</span>
+										<Switch
+											checked={enhancements[id]}
+											aria-label={option.label}
+											onCheckedChange={(enabled) =>
+												setEnhancementEnabled({ id, enabled })
+											}
+										/>
+									</div>
+								);
+							})}
+						</div>
+					</div>
+				</div>
+			</PopoverContent>
+		</Popover>
+	);
+}
diff --git a/apps/web/src/voiceover/voiceover-store.ts b/apps/web/src/voiceover/voiceover-store.ts
index 44ccae6c..e4024c1e 100644
--- a/apps/web/src/voiceover/voiceover-store.ts
+++ b/apps/web/src/voiceover/voiceover-store.ts
@@ -6,18 +6,37 @@
  */
 
 import { create } from "zustand";
+import { persist } from "zustand/middleware";
 import type { MediaTime } from "@/wasm";
+import {
+	DEFAULT_VOICE_OVER_ENHANCEMENTS,
+	type VoiceOverEnhancementSettings,
+} from "@/voiceover/enhancements";
 
-export type VoiceOverStatus = "idle" | "recording";
+export type VoiceOverStatus = "idle" | "recording" | "processing";
 
 interface VoiceOverStore {
 	status: VoiceOverStatus;
 	startedAtMs: number | null;
 	playheadStartTime: MediaTime | null;
 	startRecording: ({ playheadTime }: { playheadTime: MediaTime }) => void;
+	processRecording: () => void;
 	stopRecording: () => void;
 }
 
+interface VoiceOverPreferencesStore {
+	selectedDeviceId: string | null;
+	enhancements: VoiceOverEnhancementSettings;
+	setSelectedDeviceId: ({ deviceId }: { deviceId: string | null }) => void;
+	setEnhancementEnabled: ({
+		id,
+		enabled,
+	}: {
+		id: keyof VoiceOverEnhancementSettings;
+		enabled: boolean;
+	}) => void;
+}
+
 export const useVoiceOverStore = create<VoiceOverStore>()((set) => ({
 	status: "idle",
 	startedAtMs: null,
@@ -31,6 +50,13 @@ export const useVoiceOverStore = create<VoiceOverStore>()((set) => ({
 		});
 	},
 
+	processRecording: () => {
+		set({
+			status: "processing",
+			startedAtMs: null,
+		});
+	},
+
 	stopRecording: () => {
 		set({
 			status: "idle",
@@ -39,3 +65,32 @@ export const useVoiceOverStore = create<VoiceOverStore>()((set) => ({
 		});
 	},
 }));
+
+export const useVoiceOverPreferencesStore = create<VoiceOverPreferencesStore>()(
+	persist(
+		(set) => ({
+			selectedDeviceId: null,
+			enhancements: DEFAULT_VOICE_OVER_ENHANCEMENTS,
+
+			setSelectedDeviceId: ({ deviceId }) => {
+				set({ selectedDeviceId: deviceId });
+			},
+
+			setEnhancementEnabled: ({ id, enabled }) => {
+				set((state) => ({
+					enhancements: {
+						...state.enhancements,
+						[id]: enabled,
+					},
+				}));
+			},
+		}),
+		{
+			name: "voiceover-preferences-store",
+			partialize: (state) => ({
+				selectedDeviceId: state.selectedDeviceId,
+				enhancements: state.enhancements,
+			}),
+		},
+	),
+);
-- 
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