Add dark and light theme with OS preference support

Follow OS color scheme by default, with a three-way toggle
(System / Light / Dark) in the kebab menu. Light theme uses warm,
neutral tones with soft card-to-background contrast. Semantic colors
(damage, healing, conditions) keep their hue across themes.

Closes #10

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/src/App.tsx

@@ -30,6 +30,8 @@ import { useBulkImport } from "./hooks/use-bulk-import";
 import { useEncounter } from "./hooks/use-encounter";
 import { usePlayerCharacters } from "./hooks/use-player-characters";
 import { useSidePanelState } from "./hooks/use-side-panel-state";
+import { useTheme } from "./hooks/use-theme";
+import { cn } from "./lib/utils";
 
 function rollDice(): number {
 	return Math.floor(Math.random() * 20) + 1;
@@ -53,12 +55,12 @@ function useActionBarAnimation(combatantCount: number) {
 	}, [combatantCount]);
 
 	const empty = combatantCount === 0;
-	const risingClass = rising ? " animate-rise-to-center" : "";
-	const settlingClass = settling ? " animate-settle-to-bottom" : "";
+	const risingClass = rising ? "animate-rise-to-center" : "";
+	const settlingClass = settling ? "animate-settle-to-bottom" : "";
 	const exitingClass = topBarExiting
-		? " absolute inset-x-0 top-0 z-10 px-4 animate-slide-up-out"
+		? "absolute inset-x-0 top-0 z-10 px-4 animate-slide-up-out"
 		: "";
-	const topBarClass = settling ? " animate-slide-down-in" : exitingClass;
+	const topBarClass = settling ? "animate-slide-down-in" : exitingClass;
 	const showTopBar = !empty || topBarExiting;
 
 	return {
@@ -114,8 +116,10 @@ export function App() {
 
 	const bulkImport = useBulkImport();
 	const sidePanel = useSidePanelState();
+	const { preference: themePreference, cycleTheme } = useTheme();
 
 	const [rollSkippedCount, setRollSkippedCount] = useState(0);
+	const [rollSingleSkipped, setRollSingleSkipped] = useState(false);
 
 	const selectedCreature: Creature | null = sidePanel.selectedCreatureId
 		? (getCreature(sidePanel.selectedCreatureId) ?? null)
@@ -127,9 +131,12 @@ export function App() {
 
 	const handleAddFromBestiary = useCallback(
 		(result: SearchResult) => {
-			addFromBestiary(result);
+			const creatureId = addFromBestiary(result);
+			if (creatureId && sidePanel.panelView.mode === "closed") {
+				sidePanel.showCreature(creatureId);
+			}
 		},
-		[addFromBestiary],
+		[addFromBestiary, sidePanel.panelView.mode, sidePanel.showCreature],
 	);
 
 	const handleCombatantStatBlock = useCallback(
@@ -141,9 +148,21 @@ export function App() {
 
 	const handleRollInitiative = useCallback(
 		(id: CombatantId) => {
-			rollInitiativeUseCase(makeStore(), id, rollDice(), getCreature);
+			const result = rollInitiativeUseCase(
+				makeStore(),
+				id,
+				rollDice(),
+				getCreature,
+			);
+			if (isDomainError(result)) {
+				setRollSingleSkipped(true);
+				const combatant = encounter.combatants.find((c) => c.id === id);
+				if (combatant?.creatureId) {
+					sidePanel.showCreature(combatant.creatureId);
+				}
+			}
 		},
-		[makeStore, getCreature],
+		[makeStore, getCreature, encounter.combatants, sidePanel.showCreature],
 	);
 
 	const handleRollAllInitiative = useCallback(() => {
@@ -186,6 +205,15 @@ export function App() {
 	const playerCharacterRef = useRef<PlayerCharacterSectionHandle>(null);
 	const actionBarAnim = useActionBarAnimation(encounter.combatants.length);
 
+	// Auto-update stat block panel when the active combatant changes
+	const activeCreatureId =
+		encounter.combatants[encounter.activeIndex]?.creatureId;
+	useEffect(() => {
+		if (activeCreatureId && sidePanel.panelView.mode === "creature") {
+			sidePanel.showCreature(activeCreatureId);
+		}
+	}, [activeCreatureId, sidePanel.panelView.mode, sidePanel.showCreature]);
+
 	// Auto-scroll to the active combatant when the turn changes
 	const activeRowRef = useRef<HTMLDivElement>(null);
 	useEffect(() => {
@@ -200,7 +228,7 @@ export function App() {
 			<div className="relative mx-auto flex min-h-0 w-full max-w-2xl flex-1 flex-col gap-3 px-4">
 				{!!actionBarAnim.showTopBar && (
 					<div
-						className={`shrink-0 pt-8${actionBarAnim.topBarClass}`}
+						className={cn("shrink-0 pt-8", actionBarAnim.topBarClass)}
 						onAnimationEnd={actionBarAnim.onTopBarExitEnd}
 					>
 						<TurnNavigation
@@ -216,7 +244,7 @@ export function App() {
 					/* Empty state — ActionBar centered */
 					<div className="flex min-h-0 flex-1 items-center justify-center pt-8 pb-[15%]">
 						<div
-							className={`w-full${actionBarAnim.risingClass}`}
+							className={cn("w-full", actionBarAnim.risingClass)}
 							onAnimationEnd={actionBarAnim.onRiseEnd}
 						>
 							<ActionBar
@@ -237,6 +265,8 @@ export function App() {
 								showRollAllInitiative={hasCreatureCombatants}
 								rollAllInitiativeDisabled={!canRollAllInitiative}
 								onOpenSourceManager={sidePanel.showSourceManager}
+								themePreference={themePreference}
+								onCycleTheme={cycleTheme}
 								autoFocus
 							/>
 						</div>
@@ -265,6 +295,9 @@ export function App() {
 												? () => handleCombatantStatBlock(c.creatureId as string)
 												: undefined
 										}
+										isStatBlockOpen={
+											c.creatureId === sidePanel.selectedCreatureId
+										}
 										onRollInitiative={
 											c.creatureId ? handleRollInitiative : undefined
 										}
@@ -275,7 +308,7 @@ export function App() {
 
 						{/* Action Bar — fixed at bottom */}
 						<div
-							className={`shrink-0 pb-8${actionBarAnim.settlingClass}`}
+							className={cn("shrink-0 pb-8", actionBarAnim.settlingClass)}
 							onAnimationEnd={actionBarAnim.onSettleEnd}
 						>
 							<ActionBar
@@ -296,6 +329,8 @@ export function App() {
 								showRollAllInitiative={hasCreatureCombatants}
 								rollAllInitiativeDisabled={!canRollAllInitiative}
 								onOpenSourceManager={sidePanel.showSourceManager}
+								themePreference={themePreference}
+								onCycleTheme={cycleTheme}
 							/>
 						</div>
 					</>
@@ -359,6 +394,14 @@ export function App() {
 				/>
 			)}
 
+			{!!rollSingleSkipped && (
+				<Toast
+					message="Can't roll — bestiary source not loaded"
+					onDismiss={() => setRollSingleSkipped(false)}
+					autoDismissMs={4000}
+				/>
+			)}
+
 			<PlayerCharacterSection
 				ref={playerCharacterRef}
 				characters={playerCharacters}

apps/web/src/components/__tests__/combatant-row.test.tsx

@@ -75,7 +75,7 @@ describe("CombatantRow", () => {
 	it("active combatant gets active border styling", () => {
 		const { container } = renderRow({ isActive: true });
 		const row = container.firstElementChild;
-		expect(row?.className).toContain("border-l-accent");
+		expect(row?.className).toContain("border-active-row-border");
 	});
 
 	it("unconscious combatant (currentHp === 0) gets dimmed styling", () => {

apps/web/src/components/action-bar.tsx

@@ -6,7 +6,10 @@ import {
 	Import,
 	Library,
 	Minus,
+	Monitor,
+	Moon,
 	Plus,
+	Sun,
 	Users,
 } from "lucide-react";
 import React, { type RefObject, useDeferredValue, useState } from "react";
@@ -43,6 +46,8 @@ interface ActionBarProps {
 	rollAllInitiativeDisabled?: boolean;
 	onOpenSourceManager?: () => void;
 	autoFocus?: boolean;
+	themePreference?: "system" | "light" | "dark";
+	onCycleTheme?: () => void;
 }
 
 function creatureKey(r: SearchResult): string {
@@ -77,7 +82,7 @@ function AddModeSuggestions({
 	onAddFromPlayerCharacter?: (pc: PlayerCharacter) => void;
 }>) {
 	return (
-		<div className="absolute bottom-full z-50 mb-1 w-full max-w-xs rounded-md border border-border bg-card shadow-lg">
+		<div className="card-glow absolute bottom-full z-50 mb-1 w-full max-w-xs rounded-lg border border-border bg-card">
 			<button
 				type="button"
 				className="flex w-full items-center gap-1.5 border-border border-b px-3 py-2 text-left text-accent text-sm hover:bg-accent/20"
@@ -137,12 +142,14 @@ function AddModeSuggestions({
 								<li key={key}>
 									<button
 										type="button"
-										className={`flex w-full items-center justify-between px-3 py-1.5 text-left text-sm ${(() => {
-											if (isQueued) return "bg-accent/30 text-foreground";
-											if (i === suggestionIndex)
-												return "bg-accent/20 text-foreground";
-											return "text-foreground hover:bg-hover-neutral-bg";
-										})()}`}
+										className={cn(
+											"flex w-full items-center justify-between px-3 py-1.5 text-left text-foreground text-sm",
+											isQueued && "bg-accent/30",
+											!isQueued && i === suggestionIndex && "bg-accent/20",
+											!isQueued &&
+												i !== suggestionIndex &&
+												"hover:bg-hover-neutral-bg",
+										)}
 										onMouseDown={(e) => e.preventDefault()}
 										onClick={() => onClickSuggestion(result)}
 										onMouseEnter={() => onSetSuggestionIndex(i)}
@@ -169,7 +176,7 @@ function AddModeSuggestions({
 													>
 														<Minus className="h-3 w-3" />
 													</button>
-													<span className="min-w-5 rounded-full bg-accent px-1.5 py-0.5 text-center font-medium text-foreground">
+													<span className="min-w-5 rounded-full bg-accent px-1.5 py-0.5 text-center font-medium text-primary-foreground">
 														{queued.count}
 													</span>
 													<button
@@ -213,12 +220,26 @@ function AddModeSuggestions({
 	);
 }
 
+const THEME_ICONS = {
+	system: Monitor,
+	light: Sun,
+	dark: Moon,
+} as const;
+
+const THEME_LABELS = {
+	system: "Theme: System",
+	light: "Theme: Light",
+	dark: "Theme: Dark",
+} as const;
+
 function buildOverflowItems(opts: {
 	onManagePlayers?: () => void;
 	onOpenSourceManager?: () => void;
 	bestiaryLoaded: boolean;
 	onBulkImport?: () => void;
 	bulkImportDisabled?: boolean;
+	themePreference?: "system" | "light" | "dark";
+	onCycleTheme?: () => void;
 }): OverflowMenuItem[] {
 	const items: OverflowMenuItem[] = [];
 	if (opts.onManagePlayers) {
@@ -243,6 +264,16 @@ function buildOverflowItems(opts: {
 			disabled: opts.bulkImportDisabled,
 		});
 	}
+	if (opts.onCycleTheme) {
+		const pref = opts.themePreference ?? "system";
+		const ThemeIcon = THEME_ICONS[pref];
+		items.push({
+			icon: <ThemeIcon className="h-4 w-4" />,
+			label: THEME_LABELS[pref],
+			onClick: opts.onCycleTheme,
+			keepOpen: true,
+		});
+	}
 	return items;
 }
 
@@ -263,6 +294,8 @@ export function ActionBar({
 	rollAllInitiativeDisabled,
 	onOpenSourceManager,
 	autoFocus,
+	themePreference,
+	onCycleTheme,
 }: Readonly<ActionBarProps>) {
 	const [nameInput, setNameInput] = useState("");
 	const [suggestions, setSuggestions] = useState<SearchResult[]>([]);
@@ -452,10 +485,12 @@ export function ActionBar({
 		bestiaryLoaded,
 		onBulkImport,
 		bulkImportDisabled,
+		themePreference,
+		onCycleTheme,
 	});
 
 	return (
-		<div className="flex items-center gap-3 rounded-md border border-border bg-card px-4 py-3">
+		<div className="card-glow flex items-center gap-3 rounded-lg border border-border bg-card px-4 py-3">
 			<form
 				onSubmit={handleAdd}
 				className="relative flex flex-1 items-center gap-2"
@@ -496,17 +531,18 @@ export function ActionBar({
 							</button>
 						)}
 						{browseMode && deferredSuggestions.length > 0 && (
-							<div className="absolute bottom-full z-50 mb-1 w-full rounded-md border border-border bg-card shadow-lg">
+							<div className="card-glow absolute bottom-full z-50 mb-1 w-full rounded-lg border border-border bg-card">
 								<ul className="max-h-48 overflow-y-auto py-1">
 									{deferredSuggestions.map((result, i) => (
 										<li key={creatureKey(result)}>
 											<button
 												type="button"
-												className={`flex w-full items-center justify-between px-3 py-1.5 text-left text-sm ${
+												className={cn(
+													"flex w-full items-center justify-between px-3 py-1.5 text-left text-sm",
 													i === suggestionIndex
 														? "bg-accent/20 text-foreground"
-														: "text-foreground hover:bg-hover-neutral-bg"
-												}`}
+														: "text-foreground hover:bg-hover-neutral-bg",
+												)}
 												onMouseDown={(e) => e.preventDefault()}
 												onClick={() => handleBrowseSelect(result)}
 												onMouseEnter={() => setSuggestionIndex(i)}

apps/web/src/components/combatant-row.tsx

@@ -4,7 +4,7 @@ import {
 	deriveHpStatus,
 	type PlayerIcon,
 } from "@initiative/domain";
-import { BookOpen, Brain, X } from "lucide-react";
+import { Book, BookOpen, Brain, X } from "lucide-react";
 import { type Ref, useCallback, useEffect, useRef, useState } from "react";
 import { cn } from "../lib/utils";
 import { AcShield } from "./ac-shield";
@@ -41,6 +41,7 @@ interface CombatantRowProps {
 	onToggleCondition: (id: CombatantId, conditionId: ConditionId) => void;
 	onToggleConcentration: (id: CombatantId) => void;
 	onShowStatBlock?: () => void;
+	isStatBlockOpen?: boolean;
 	onRollInitiative?: (id: CombatantId) => void;
 }
 
@@ -79,7 +80,7 @@ function EditableName({
 				ref={inputRef}
 				type="text"
 				value={draft}
-				className="h-7 text-sm"
+				className="h-7 max-w-48 text-sm"
 				onChange={(e) => setDraft(e.target.value)}
 				onBlur={commit}
 				onKeyDown={(e) => {
@@ -365,9 +366,13 @@ function rowBorderClass(
 	isActive: boolean,
 	isConcentrating: boolean | undefined,
 ): string {
-	if (isActive) return "border-l-2 border-l-accent bg-accent/10";
-	if (isConcentrating) return "border-l-2 border-l-purple-400";
-	return "border-l-2 border-l-transparent";
+	if (isActive && isConcentrating)
+		return "border border-l-2 border-active-row-border border-l-purple-400 bg-active-row-bg card-glow";
+	if (isActive)
+		return "border border-l-2 border-active-row-border bg-active-row-bg card-glow";
+	if (isConcentrating)
+		return "border border-l-2 border-transparent border-l-purple-400";
+	return "border border-l-2 border-transparent";
 }
 
 function concentrationIconClass(
@@ -392,6 +397,7 @@ export function CombatantRow({
 	onToggleCondition,
 	onToggleConcentration,
 	onShowStatBlock,
+	isStatBlockOpen,
 	onRollInitiative,
 }: CombatantRowProps & { ref?: Ref<HTMLDivElement> }) {
 	const { id, name, initiative, maxHp, currentHp } = combatant;
@@ -434,7 +440,7 @@ export function CombatantRow({
 		<div
 			ref={ref}
 			className={cn(
-				"group rounded-md pr-3 transition-colors",
+				"group rounded-lg pr-3 transition-colors",
 				rowBorderClass(isActive, combatant.isConcentrating),
 				isPulsing && "animate-concentration-pulse",
 			)}
@@ -476,9 +482,9 @@ export function CombatantRow({
 							onClick={onShowStatBlock}
 							title="View stat block"
 							aria-label="View stat block"
-							className="shrink-0 text-muted-foreground transition-colors hover:text-hover-neutral"
+							className="shrink-0 text-foreground transition-colors hover:text-hover-neutral"
 						>
-							<BookOpen size={14} />
+							{isStatBlockOpen ? <BookOpen size={16} /> : <Book size={16} />}
 						</button>
 					)}
 					{!!combatant.icon &&
@@ -491,7 +497,7 @@ export function CombatantRow({
 								];
 							return PcIcon ? (
 								<PcIcon
-									size={14}
+									size={16}
 									style={{ color: iconColor }}
 									className="shrink-0"
 								/>

apps/web/src/components/condition-picker.tsx

@@ -97,7 +97,7 @@ export function ConditionPicker({
 		<div
 			ref={ref}
 			className={cn(
-				"absolute left-0 z-10 w-fit overflow-y-auto rounded-md border border-border bg-background p-1 shadow-lg",
+				"card-glow absolute left-0 z-10 w-fit overflow-y-auto rounded-lg border border-border bg-background p-1",
 				flipped ? "bottom-full mb-1" : "top-full mt-1",
 			)}
 			style={maxHeight ? { maxHeight } : undefined}

apps/web/src/components/condition-tags.tsx

@@ -18,6 +18,7 @@ import {
 	Sparkles,
 	ZapOff,
 } from "lucide-react";
+import { cn } from "../lib/utils.js";
 
 const ICON_MAP: Record<string, LucideIcon> = {
 	EyeOff,
@@ -75,7 +76,10 @@ export function ConditionTags({
 						type="button"
 						title={def.label}
 						aria-label={`Remove ${def.label}`}
-						className={`inline-flex items-center rounded p-0.5 transition-colors hover:bg-hover-neutral-bg ${colorClass}`}
+						className={cn(
+							"inline-flex items-center rounded p-0.5 transition-colors hover:bg-hover-neutral-bg",
+							colorClass,
+						)}
 						onClick={(e) => {
 							e.stopPropagation();
 							onRemove(condId);

apps/web/src/components/create-player-modal.tsx

@@ -106,7 +106,7 @@ export function CreatePlayerModal({
 	return (
 		<dialog
 			ref={dialogRef}
-			className="w-full max-w-md rounded-lg border border-border bg-card p-6 shadow-xl backdrop:bg-black/50"
+			className="card-glow m-auto w-full max-w-md rounded-lg border border-border bg-card p-6 backdrop:bg-black/50"
 		>
 			<div className="mb-4 flex items-center justify-between">
 				<h2 className="font-semibold text-foreground text-lg">

apps/web/src/components/hp-adjust-popover.tsx

@@ -87,7 +87,7 @@ export function HpAdjustPopover({ onAdjust, onClose }: HpAdjustPopoverProps) {
 	return (
 		<div
 			ref={ref}
-			className="fixed z-10 rounded-md border border-border bg-background p-2 shadow-lg"
+			className="card-glow fixed z-10 rounded-lg border border-border bg-background p-2"
 			style={
 				pos
 					? { top: pos.top, left: pos.left }
@@ -113,7 +113,7 @@ export function HpAdjustPopover({ onAdjust, onClose }: HpAdjustPopoverProps) {
 				<button
 					type="button"
 					disabled={!isValid}
-					className="inline-flex h-7 w-7 shrink-0 items-center justify-center rounded-md text-red-400 transition-colors hover:bg-red-950 hover:text-red-300 disabled:pointer-events-none disabled:opacity-50"
+					className="inline-flex h-7 w-7 shrink-0 items-center justify-center rounded-md text-red-400 transition-colors hover:bg-hp-damage-hover-bg hover:text-red-300 disabled:pointer-events-none disabled:opacity-50"
 					onClick={() => applyDelta(-1)}
 					title="Apply damage"
 					aria-label="Apply damage"
@@ -123,7 +123,7 @@ export function HpAdjustPopover({ onAdjust, onClose }: HpAdjustPopoverProps) {
 				<button
 					type="button"
 					disabled={!isValid}
-					className="inline-flex h-7 w-7 shrink-0 items-center justify-center rounded-md text-emerald-400 transition-colors hover:bg-emerald-950 hover:text-emerald-300 disabled:pointer-events-none disabled:opacity-50"
+					className="inline-flex h-7 w-7 shrink-0 items-center justify-center rounded-md text-emerald-400 transition-colors hover:bg-hp-heal-hover-bg hover:text-emerald-300 disabled:pointer-events-none disabled:opacity-50"
 					onClick={() => applyDelta(1)}
 					title="Apply healing"
 					aria-label="Apply healing"

apps/web/src/components/player-management.tsx

@@ -55,7 +55,7 @@ export function PlayerManagement({
 	return (
 		<dialog
 			ref={dialogRef}
-			className="w-full max-w-md rounded-lg border border-border bg-card p-6 shadow-xl backdrop:bg-black/50"
+			className="card-glow m-auto w-full max-w-md rounded-lg border border-border bg-card p-6 backdrop:bg-black/50"
 		>
 			<div className="mb-4 flex items-center justify-between">
 				<h2 className="font-semibold text-foreground text-lg">

apps/web/src/components/source-manager.tsx

@@ -1,8 +1,15 @@
-import { Database, Trash2 } from "lucide-react";
-import { useCallback, useEffect, useOptimistic, useState } from "react";
+import { Database, Search, Trash2 } from "lucide-react";
+import {
+	useCallback,
+	useEffect,
+	useMemo,
+	useOptimistic,
+	useState,
+} from "react";
 import type { CachedSourceInfo } from "../adapters/bestiary-cache.js";
 import * as bestiaryCache from "../adapters/bestiary-cache.js";
 import { Button } from "./ui/button.js";
+import { Input } from "./ui/input.js";
 
 interface SourceManagerProps {
 	onCacheCleared: () => void;
@@ -12,6 +19,7 @@ export function SourceManager({
 	onCacheCleared,
 }: Readonly<SourceManagerProps>) {
 	const [sources, setSources] = useState<CachedSourceInfo[]>([]);
+	const [filter, setFilter] = useState("");
 	const [optimisticSources, applyOptimistic] = useOptimistic(
 		sources,
 		(
@@ -46,6 +54,15 @@ export function SourceManager({
 		onCacheCleared();
 	};
 
+	const filteredSources = useMemo(() => {
+		const term = filter.toLowerCase();
+		return term
+			? optimisticSources.filter((s) =>
+					s.displayName.toLowerCase().includes(term),
+				)
+			: optimisticSources;
+	}, [optimisticSources, filter]);
+
 	if (optimisticSources.length === 0) {
 		return (
 			<div className="flex flex-col items-center gap-2 py-8 text-center">
@@ -70,8 +87,17 @@ export function SourceManager({
 					Clear All
 				</Button>
 			</div>
+			<div className="relative">
+				<Search className="pointer-events-none absolute top-1/2 left-3 h-3.5 w-3.5 -translate-y-1/2 text-muted-foreground" />
+				<Input
+					placeholder="Filter sources…"
+					value={filter}
+					onChange={(e) => setFilter(e.target.value)}
+					className="pl-8"
+				/>
+			</div>
 			<ul className="flex flex-col gap-1">
-				{optimisticSources.map((source) => (
+				{filteredSources.map((source) => (
 					<li
 						key={source.sourceCode}
 						className="flex items-center justify-between rounded-md border border-border px-3 py-2"

apps/web/src/components/stat-block-panel.tsx

@@ -5,6 +5,7 @@ import { useEffect, useState } from "react";
 import { getSourceDisplayName } from "../adapters/bestiary-index-adapter.js";
 import type { BulkImportState } from "../hooks/use-bulk-import.js";
 import { useSwipeToDismiss } from "../hooks/use-swipe-to-dismiss.js";
+import { cn } from "../lib/utils.js";
 import { BulkImportPrompt } from "./bulk-import-prompt.js";
 import { SourceFetchPrompt } from "./source-fetch-prompt.js";
 import { SourceManager } from "./source-manager.js";
@@ -55,9 +56,10 @@ function CollapsedTab({
 		<button
 			type="button"
 			onClick={onToggleCollapse}
-			className={`flex h-full w-[40px] cursor-pointer items-center justify-center text-muted-foreground hover:text-hover-neutral ${
-				side === "right" ? "self-start" : "self-end"
-			}`}
+			className={cn(
+				"flex h-full w-[40px] cursor-pointer items-center justify-center text-muted-foreground hover:text-hover-neutral",
+				side === "right" ? "self-start" : "self-end",
+			)}
 			aria-label="Expand stat block panel"
 		>
 			<span className="writing-vertical-rl font-medium text-sm">
@@ -152,7 +154,11 @@ function DesktopPanel({
 
 	return (
 		<div
-			className={`fixed top-0 bottom-0 flex w-[400px] flex-col border-border bg-card transition-slide-panel ${sideClasses} ${isCollapsed ? collapsedTranslate : "translate-x-0"}`}
+			className={cn(
+				"panel-glow fixed top-0 bottom-0 flex w-[400px] flex-col border-border bg-card transition-slide-panel",
+				sideClasses,
+				isCollapsed ? collapsedTranslate : "translate-x-0",
+			)}
 		>
 			{isCollapsed ? (
 				<CollapsedTab
@@ -194,7 +200,10 @@ function MobileDrawer({
 				aria-label="Close stat block"
 			/>
 			<div
-				className={`absolute top-0 right-0 bottom-0 w-[85%] max-w-md border-border border-l bg-card shadow-xl ${isSwiping ? "" : "animate-slide-in-right"}`}
+				className={cn(
+					"panel-glow absolute top-0 right-0 bottom-0 w-[85%] max-w-md border-border border-l bg-card",
+					!isSwiping && "animate-slide-in-right",
+				)}
 				style={
 					isSwiping ? { transform: `translateX(${offsetX}px)` } : undefined
 				}

apps/web/src/components/stat-block.tsx

@@ -30,7 +30,7 @@ function PropertyLine({
 
 function SectionDivider() {
 	return (
-		<div className="my-2 h-px bg-gradient-to-r from-amber-800/60 via-amber-700/40 to-transparent" />
+		<div className="my-2 h-px bg-gradient-to-r from-stat-divider-from via-stat-divider-via to-transparent" />
 	);
 }
 
@@ -54,7 +54,7 @@ export function StatBlock({ creature }: Readonly<StatBlockProps>) {
 		<div className="space-y-1 text-foreground">
 			{/* Header */}
 			<div>
-				<h2 className="font-bold text-amber-400 text-xl">{creature.name}</h2>
+				<h2 className="font-bold text-stat-heading text-xl">{creature.name}</h2>
 				<p className="text-muted-foreground text-sm italic">
 					{creature.size} {creature.type}, {creature.alignment}
 				</p>
@@ -194,7 +194,7 @@ export function StatBlock({ creature }: Readonly<StatBlockProps>) {
 			{creature.actions && creature.actions.length > 0 && (
 				<>
 					<SectionDivider />
-					<h3 className="font-bold text-amber-400 text-base">Actions</h3>
+					<h3 className="font-bold text-base text-stat-heading">Actions</h3>
 					<div className="space-y-2">
 						{creature.actions.map((a) => (
 							<div key={a.name} className="text-sm">
@@ -209,7 +209,9 @@ export function StatBlock({ creature }: Readonly<StatBlockProps>) {
 			{creature.bonusActions && creature.bonusActions.length > 0 && (
 				<>
 					<SectionDivider />
-					<h3 className="font-bold text-amber-400 text-base">Bonus Actions</h3>
+					<h3 className="font-bold text-base text-stat-heading">
+						Bonus Actions
+					</h3>
 					<div className="space-y-2">
 						{creature.bonusActions.map((a) => (
 							<div key={a.name} className="text-sm">
@@ -224,7 +226,7 @@ export function StatBlock({ creature }: Readonly<StatBlockProps>) {
 			{creature.reactions && creature.reactions.length > 0 && (
 				<>
 					<SectionDivider />
-					<h3 className="font-bold text-amber-400 text-base">Reactions</h3>
+					<h3 className="font-bold text-base text-stat-heading">Reactions</h3>
 					<div className="space-y-2">
 						{creature.reactions.map((a) => (
 							<div key={a.name} className="text-sm">
@@ -239,7 +241,7 @@ export function StatBlock({ creature }: Readonly<StatBlockProps>) {
 			{!!creature.legendaryActions && (
 				<>
 					<SectionDivider />
-					<h3 className="font-bold text-amber-400 text-base">
+					<h3 className="font-bold text-base text-stat-heading">
 						Legendary Actions
 					</h3>
 					<p className="text-muted-foreground text-sm italic">

apps/web/src/components/toast.tsx

@@ -24,7 +24,7 @@ export function Toast({
 
 	return createPortal(
 		<div className="fixed bottom-4 left-4 z-50">
-			<div className="flex items-center gap-3 rounded-lg border border-border bg-card px-4 py-3 shadow-lg">
+			<div className="card-glow flex items-center gap-3 rounded-lg border border-border bg-card px-4 py-3">
 				<span className="text-foreground text-sm">{message}</span>
 				{progress !== undefined && (
 					<div className="h-2 w-24 overflow-hidden rounded-full bg-muted">

apps/web/src/components/turn-navigation.tsx

@@ -21,9 +21,9 @@ export function TurnNavigation({
 	const activeCombatant = encounter.combatants[encounter.activeIndex];
 
 	return (
-		<div className="flex items-center gap-3 rounded-md border border-border bg-card px-4 py-3">
+		<div className="card-glow flex items-center gap-3 rounded-lg border border-border bg-card px-4 py-3">
 			<Button
-				variant="outline"
+				variant="ghost"
 				size="icon"
 				onClick={onRetreatTurn}
 				disabled={!hasCombatants || isAtStart}
@@ -53,7 +53,7 @@ export function TurnNavigation({
 					className="text-muted-foreground"
 				/>
 				<Button
-					variant="outline"
+					variant="ghost"
 					size="icon"
 					onClick={onAdvanceTurn}
 					disabled={!hasCombatants}

apps/web/src/components/ui/button.tsx

@@ -9,8 +9,9 @@ const buttonVariants = cva(
 			variant: {
 				default: "bg-primary text-primary-foreground hover:bg-primary/90",
 				outline:
-					"border border-border bg-transparent hover:bg-hover-neutral-bg hover:text-hover-neutral",
-				ghost: "hover:bg-hover-neutral-bg hover:text-hover-neutral",
+					"border border-border bg-background/50 text-foreground hover:bg-hover-neutral-bg hover:text-hover-neutral",
+				ghost:
+					"text-foreground hover:bg-hover-neutral-bg hover:text-hover-neutral",
 			},
 			size: {
 				default: "h-8 px-3 text-xs",

apps/web/src/components/ui/overflow-menu.tsx

@@ -7,6 +7,7 @@ export interface OverflowMenuItem {
 	readonly label: string;
 	readonly onClick: () => void;
 	readonly disabled?: boolean;
+	readonly keepOpen?: boolean;
 }
 
 interface OverflowMenuProps {
@@ -49,7 +50,7 @@ export function OverflowMenu({ items }: OverflowMenuProps) {
 				<EllipsisVertical className="h-5 w-5" />
 			</Button>
 			{!!open && (
-				<div className="absolute right-0 bottom-full z-50 mb-1 min-w-48 rounded-md border border-border bg-card py-1 shadow-lg">
+				<div className="card-glow absolute right-0 bottom-full z-50 mb-1 min-w-48 rounded-lg border border-border bg-card py-1">
 					{items.map((item) => (
 						<button
 							key={item.label}
@@ -58,7 +59,7 @@ export function OverflowMenu({ items }: OverflowMenuProps) {
 							disabled={item.disabled}
 							onClick={() => {
 								item.onClick();
-								setOpen(false);
+								if (!item.keepOpen) setOpen(false);
 							}}
 						>
 							{item.icon}

apps/web/src/hooks/__tests__/use-encounter.test.ts

@@ -137,7 +137,9 @@ describe("useEncounter", () => {
 			type: "humanoid",
 		};
 
-		act(() => result.current.addFromBestiary(entry));
+		act(() => {
+			result.current.addFromBestiary(entry);
+		});
 
 		expect(result.current.hasCreatureCombatants).toBe(true);
 		expect(result.current.canRollAllInitiative).toBe(true);
@@ -158,7 +160,9 @@ describe("useEncounter", () => {
 			type: "humanoid",
 		};
 
-		act(() => result.current.addFromBestiary(entry));
+		act(() => {
+			result.current.addFromBestiary(entry);
+		});
 
 		const combatant = result.current.encounter.combatants[0];
 		expect(combatant.name).toBe("Goblin");
@@ -183,8 +187,12 @@ describe("useEncounter", () => {
 			type: "humanoid",
 		};
 
-		act(() => result.current.addFromBestiary(entry));
-		act(() => result.current.addFromBestiary(entry));
+		act(() => {
+			result.current.addFromBestiary(entry);
+		});
+		act(() => {
+			result.current.addFromBestiary(entry);
+		});
 
 		const names = result.current.encounter.combatants.map((c) => c.name);
 		expect(names).toContain("Goblin 1");

apps/web/src/hooks/use-encounter.ts

@@ -17,6 +17,7 @@ import type {
 	BestiaryIndexEntry,
 	CombatantId,
 	ConditionId,
+	CreatureId,
 	DomainEvent,
 	Encounter,
 	PlayerCharacter,
@@ -265,7 +266,7 @@ export function useEncounter() {
 	}, [makeStore]);
 
 	const addFromBestiary = useCallback(
-		(entry: BestiaryIndexEntry) => {
+		(entry: BestiaryIndexEntry): CreatureId | null => {
 			const store = makeStore();
 			const existingNames = store.get().combatants.map((c) => c.name);
 			const { newName, renames } = resolveCreatureName(
@@ -284,7 +285,7 @@ export function useEncounter() {
 			// Add combatant with resolved name
 			const id = combatantId(`c-${++nextId.current}`);
 			const addResult = addCombatantUseCase(makeStore(), id, newName);
-			if (isDomainError(addResult)) return;
+			if (isDomainError(addResult)) return null;
 
 			// Set HP
 			const hpResult = setHpUseCase(makeStore(), id, entry.hp);
@@ -317,6 +318,8 @@ export function useEncounter() {
 			});
 
 			setEvents((prev) => [...prev, ...addResult]);
+
+			return cId;
 		},
 		[makeStore],
 	);

apps/web/src/hooks/use-theme.ts

@@ -0,0 +1,98 @@
+import { useCallback, useEffect, useSyncExternalStore } from "react";
+
+type ThemePreference = "system" | "light" | "dark";
+type ResolvedTheme = "light" | "dark";
+
+const STORAGE_KEY = "initiative:theme";
+
+const listeners = new Set<() => void>();
+let currentPreference: ThemePreference = loadPreference();
+
+function loadPreference(): ThemePreference {
+	try {
+		const raw = localStorage.getItem(STORAGE_KEY);
+		if (raw === "light" || raw === "dark" || raw === "system") return raw;
+	} catch {
+		// storage unavailable
+	}
+	return "system";
+}
+
+function savePreference(pref: ThemePreference): void {
+	try {
+		localStorage.setItem(STORAGE_KEY, pref);
+	} catch {
+		// quota exceeded or storage unavailable
+	}
+}
+
+function getSystemTheme(): ResolvedTheme {
+	if (typeof globalThis.matchMedia !== "function") return "dark";
+	return globalThis.matchMedia("(prefers-color-scheme: light)").matches
+		? "light"
+		: "dark";
+}
+
+function resolve(pref: ThemePreference): ResolvedTheme {
+	return pref === "system" ? getSystemTheme() : pref;
+}
+
+function applyTheme(resolved: ResolvedTheme): void {
+	document.documentElement.dataset.theme = resolved;
+}
+
+function notifyAll(): void {
+	for (const listener of listeners) {
+		listener();
+	}
+}
+
+// Apply on load
+applyTheme(resolve(currentPreference));
+
+// Listen for OS preference changes
+if (typeof globalThis.matchMedia === "function") {
+	globalThis
+		.matchMedia("(prefers-color-scheme: light)")
+		.addEventListener("change", () => {
+			if (currentPreference === "system") {
+				applyTheme(resolve("system"));
+				notifyAll();
+			}
+		});
+}
+
+function subscribe(callback: () => void): () => void {
+	listeners.add(callback);
+	return () => listeners.delete(callback);
+}
+
+function getSnapshot(): ThemePreference {
+	return currentPreference;
+}
+
+const CYCLE: ThemePreference[] = ["system", "light", "dark"];
+
+export function useTheme() {
+	const preference = useSyncExternalStore(subscribe, getSnapshot);
+	const resolved = resolve(preference);
+
+	useEffect(() => {
+		applyTheme(resolved);
+	}, [resolved]);
+
+	const setPreference = useCallback((pref: ThemePreference) => {
+		currentPreference = pref;
+		savePreference(pref);
+		applyTheme(resolve(pref));
+		notifyAll();
+	}, []);
+
+	const cycleTheme = useCallback(() => {
+		const idx = CYCLE.indexOf(currentPreference);
+		const next = CYCLE[(idx + 1) % CYCLE.length];
+		setPreference(next);
+	}, [setPreference]);
+
+	return { preference, resolved, setPreference, cycleTheme } as const;
+}

apps/web/src/index.css

@@ -1,14 +1,14 @@
 @import "tailwindcss";
 
 @theme {
-	--color-background: #0f172a;
+	--color-background: #0e1a2e;
 	--color-foreground: #e2e8f0;
-	--color-muted: #64748b;
+	--color-muted: #7a8ba4;
 	--color-muted-foreground: #94a3b8;
-	--color-card: #1e293b;
+	--color-card: #1a2e4a;
 	--color-card-foreground: #e2e8f0;
-	--color-border: #334155;
-	--color-input: #334155;
+	--color-border: #2a5088;
+	--color-input: #2a5088;
 	--color-primary: #3b82f6;
 	--color-primary-foreground: #ffffff;
 	--color-accent: #3b82f6;
@@ -19,12 +19,47 @@
 	--color-hover-neutral-bg: oklch(0.623 0.214 259 / 0.15);
 	--color-hover-action-bg: var(--color-muted);
 	--color-hover-destructive-bg: transparent;
+	--color-stat-heading: #fbbf24;
+	--color-stat-divider-from: oklch(0.5 0.1 65 / 0.6);
+	--color-stat-divider-via: oklch(0.5 0.1 65 / 0.4);
+	--color-hp-damage-hover-bg: oklch(0.25 0.05 25);
+	--color-hp-heal-hover-bg: oklch(0.25 0.05 155);
+	--color-active-row-bg: oklch(0.623 0.214 259 / 0.1);
+	--color-active-row-border: oklch(0.623 0.214 259 / 0.4);
 	--radius-sm: 0.25rem;
-	--radius-md: 0.375rem;
-	--radius-lg: 0.5rem;
+	--radius-md: 0.5rem;
+	--radius-lg: 0.75rem;
 	--font-sans: "Inter", ui-sans-serif, system-ui, sans-serif;
 }
 
+[data-theme="light"] {
+	--color-background: #eeecea;
+	--color-foreground: #374151;
+	--color-muted: #e0ddd9;
+	--color-muted-foreground: #6b7280;
+	--color-card: #f7f6f4;
+	--color-card-foreground: #374151;
+	--color-border: #ddd9d5;
+	--color-input: #cdc8c3;
+	--color-primary: #2563eb;
+	--color-primary-foreground: #ffffff;
+	--color-accent: #2563eb;
+	--color-destructive: #dc2626;
+	--color-hover-neutral: var(--color-primary);
+	--color-hover-action: var(--color-primary);
+	--color-hover-destructive: var(--color-destructive);
+	--color-hover-neutral-bg: oklch(0.623 0.214 259 / 0.08);
+	--color-hover-action-bg: var(--color-muted);
+	--color-hover-destructive-bg: transparent;
+	--color-stat-heading: #92400e;
+	--color-stat-divider-from: oklch(0.55 0.1 65 / 0.5);
+	--color-stat-divider-via: oklch(0.55 0.1 65 / 0.25);
+	--color-hp-damage-hover-bg: #fef2f2;
+	--color-hp-heal-hover-bg: #ecfdf5;
+	--color-active-row-bg: oklch(0.623 0.214 259 / 0.08);
+	--color-active-row-border: oklch(0.623 0.214 259 / 0.25);
+}
+
 @keyframes concentration-shake {
 	0% {
 		translate: 0;
@@ -169,6 +204,38 @@
 		concentration-glow 1200ms ease-out;
 }
 
+@utility card-glow {
+	background-image: radial-gradient(
+		ellipse at 50% 50%,
+		oklch(0.35 0.05 250 / 0.5) 0%,
+		transparent 70%
+	);
+	box-shadow:
+		0 0 15px -2px oklch(0.623 0.214 259 / 0.2),
+		inset 0 1px 0 0 oklch(0.7 0.15 259 / 0.1);
+
+	[data-theme="light"] & {
+		background-image: none;
+		box-shadow: 0 1px 3px 0 oklch(0 0 0 / 0.08);
+	}
+}
+
+@utility panel-glow {
+	background-image: linear-gradient(
+		to bottom,
+		oklch(0.35 0.05 250 / 0.4) 0%,
+		transparent 40%
+	);
+	box-shadow:
+		0 0 20px -2px oklch(0.623 0.214 259 / 0.15),
+		inset 0 1px 0 0 oklch(0.7 0.15 259 / 0.1);
+
+	[data-theme="light"] & {
+		background-image: none;
+		box-shadow: -1px 0 6px 0 oklch(0 0 0 / 0.1);
+	}
+}
+
 * {
 	scrollbar-color: var(--color-border) transparent;
 	scrollbar-width: thin;
@@ -176,6 +243,16 @@
 
 body {
 	background-color: var(--color-background);
+	background-image: radial-gradient(
+		ellipse at 50% 40%,
+		oklch(0.26 0.055 250) 0%,
+		var(--color-background) 70%
+	);
+	background-attachment: fixed;
 	color: var(--color-foreground);
 	font-family: var(--font-sans);
 }
+
+[data-theme="light"] body {
+	background-image: none;
+}

package.json

@@ -30,6 +30,7 @@
 		"jscpd": "jscpd",
 		"oxlint": "oxlint --tsconfig apps/web/tsconfig.json --type-aware",
 		"check:ignores": "node scripts/check-lint-ignores.mjs",
-		"check": "pnpm audit --audit-level=high && knip && biome check . && oxlint --tsconfig apps/web/tsconfig.json --type-aware && node scripts/check-lint-ignores.mjs && tsc --build && vitest run && jscpd"
+		"check:classnames": "node scripts/check-cn-classnames.mjs",
+		"check": "pnpm audit --audit-level=high && knip && biome check . && oxlint --tsconfig apps/web/tsconfig.json --type-aware && node scripts/check-lint-ignores.mjs && node scripts/check-cn-classnames.mjs && tsc --build && vitest run && jscpd"
 	}
 }

scripts/check-cn-classnames.mjs

@@ -0,0 +1,47 @@
+/**
+ * Ban template-literal classNames in TSX files.
+ *
+ * Tailwind v4's production content extractor does static analysis on source
+ * files to discover utility classes. Template literals like
+ *   className={`foo ${bar}`}
+ * can cause the extractor to miss classes adjacent to `${`, leading to
+ * styles that work in dev (JIT) but break in production.
+ *
+ * Rule: always use cn() for dynamic class composition instead.
+ */
+
+import { execSync } from "node:child_process";
+import { readFileSync } from "node:fs";
+
+const PATTERN = /className\s*=\s*\{`/;
+
+function findFiles() {
+	return execSync("git ls-files -- '*.tsx'", { encoding: "utf-8" })
+		.trim()
+		.split("\n")
+		.filter(Boolean);
+}
+
+let errors = 0;
+
+for (const file of findFiles()) {
+	const lines = readFileSync(file, "utf-8").split("\n");
+
+	for (let i = 0; i < lines.length; i++) {
+		if (PATTERN.test(lines[i])) {
+			console.error(
+				`${file}:${i + 1}: className uses template literal — use cn() instead`,
+			);
+			errors++;
+		}
+	}
+}
+
+if (errors > 0) {
+	console.error(
+		`\n${errors} template-literal className(s) found. Use cn() for dynamic classes.`,
+	);
+	process.exit(1);
+} else {
+	console.log("No template-literal classNames found.");
+}

specs/004-bestiary/spec.md

@@ -148,7 +148,7 @@ While the bulk import is in progress, the user sees a text counter ("Loading sou
 If the user closes the side panel while a bulk import is still in progress, a persistent toast notification appears at the bottom-center of the screen showing the same progress text and progress bar.
 
 **US-M6 — Manage Cached Sources (P4)**
-A DM wants to see which sources are cached, clear a specific source's cache, or clear all cached data. A management UI provides this visibility and control.
+A DM wants to see which sources are cached, find a specific source, clear a specific source's cache, or clear all cached data. A management UI provides this visibility and control, including a filter input to quickly locate sources by name when many are cached.
 
 ### Requirements
 
@@ -174,7 +174,7 @@ A DM wants to see which sources are cached, clear a specific source's cache, or
 - **FR-044**: The bulk import MUST run asynchronously and not block the rest of the app.
 - **FR-045**: The user MUST explicitly provide/confirm the URL before any fetches occur — the app never auto-fetches content.
 - **FR-046**: The "Load All" button MUST be disabled when the URL field is empty or while a bulk import is already in progress.
-- **FR-047**: The app MUST provide a management UI showing cached sources with options to clear individual sources or all cached data.
+- **FR-047**: The app MUST provide a management UI showing cached sources with a filter input for searching by display name and options to clear individual sources or all cached data.
 - **FR-048**: The normalization adapter and tag-stripping utility MUST remain the canonical pipeline for all fetched and uploaded data.
 - **FR-049**: The distributed app bundle MUST contain zero copyrighted prose content — only mechanical facts and creature names in the search index.
 
@@ -198,6 +198,7 @@ A DM wants to see which sources are cached, clear a specific source's cache, or
 16. **Given** two sources have been cached, **When** the DM opens the source management UI, **Then** both sources are listed with their display names.
 17. **Given** the source management UI is open, **When** the DM clears a single source, **Then** that source's data is removed; stat blocks for its creatures require re-fetching, while other cached sources remain.
 18. **Given** the source management UI is open, **When** the DM clears all cached data, **Then** all source data is removed and all stat blocks require re-fetching.
+19. **Given** many sources are cached, **When** the DM types a partial name in the filter input, **Then** only sources whose display name matches (case-insensitive) are shown.
 
 ### Edge Cases
 
@@ -263,7 +264,7 @@ As a DM with a creature pinned, I want to collapse the right (browse) panel inde
 ### Edge Cases
 
 - User pins a creature and then that creature is removed from the encounter: the pinned panel continues displaying the creature's stat block (data is already loaded).
-- Active combatant changes while panel is open or collapsed: advancing turns does not auto-show or update the stat block panel. The panel only changes when the user explicitly clicks a book icon. If the panel is collapsed, it stays collapsed.
+- Active combatant changes while panel is open: if the new active combatant has a creature, the panel auto-updates to show that creature's stat block. If the new active combatant has no creature, the panel remains on the previous creature. If the panel is collapsed, it stays collapsed. If the panel is closed, it stays closed.
 - Viewport resized from wide to narrow while a creature is pinned: the pinned (left) panel is hidden and the pin button disappears; resizing back to wide restores the pinned panel.
 - User is in bulk import mode and tries to collapse: the collapse/expand behavior applies to the bulk import panel identically.
 - Panel showing a source fetch prompt: the pin button is hidden.