Add PF2e spell description popovers in stat blocks

Clicking a spell name in a PF2e creature's stat block now opens a
popover (desktop) or bottom sheet (mobile) showing full spell details:
description, traits, rank, range, target, area, duration, defense,
action cost icons, and heightening rules. All data is sourced from
the embedded Foundry VTT spell items already in the bestiary cache.

- Add SpellReference type replacing bare string spell arrays
- Extract full spell data in pf2e-bestiary-adapter (description,
  traits, traditions, range, target, area, duration, defense,
  action cost, heightening, overlays)
- Strip inline heightening text from descriptions to avoid duplication
- Bold save outcome labels (Critical Success/Failure) in descriptions
- Bump DB_VERSION to 6 for cache invalidation
- Add useSwipeToDismissDown hook for mobile bottom sheet
- Portal popover to document.body to escape transformed ancestors

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

apps/web/src/components/__tests__/pf2e-stat-block.test.tsx

@@ -4,11 +4,14 @@ import "@testing-library/jest-dom/vitest";
 import type { Pf2eCreature } from "@initiative/domain";
 import { creatureId } from "@initiative/domain";
 import { cleanup, render, screen } from "@testing-library/react";
-import { afterEach, describe, expect, it } from "vitest";
+import userEvent from "@testing-library/user-event";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { Pf2eStatBlock } from "../pf2e-stat-block.js";
 
 afterEach(cleanup);
 
+const USES_PER_DAY_REGEX = /×3/;
+const HEAL_DESCRIPTION_REGEX = /channel positive energy/;
 const PERCEPTION_SENSES_REGEX = /\+2.*Darkvision/;
 const SKILLS_REGEX = /Acrobatics \+5.*Stealth \+5/;
 const SAVE_CONDITIONAL_REGEX = /\+12.*\+1 status to all saves vs\. magic/;
@@ -90,9 +93,13 @@ const NAUNET: Pf2eCreature = {
 			name: "Divine Innate Spells",
 			headerText: "DC 25, attack +17",
 			daily: [
-				{ uses: 4, each: true, spells: ["Unfettered Movement (Constant)"] },
+				{
+					uses: 4,
+					each: true,
+					spells: [{ name: "Unfettered Movement (Constant)" }],
+				},
 			],
-			atWill: ["Detect Magic"],
+			atWill: [{ name: "Detect Magic" }],
 		},
 	],
 };
@@ -277,4 +284,87 @@ describe("Pf2eStatBlock", () => {
 			expect(screen.queryByText(CANTRIPS_REGEX)).not.toBeInTheDocument();
 		});
 	});
+
+	describe("clickable spells", () => {
+		const SPELLCASTER: Pf2eCreature = {
+			...NAUNET,
+			id: creatureId("test:spellcaster"),
+			name: "Spellcaster",
+			spellcasting: [
+				{
+					name: "Divine Innate Spells",
+					headerText: "DC 30, attack +20",
+					atWill: [{ name: "Detect Magic", rank: 1 }],
+					daily: [
+						{
+							uses: 4,
+							each: true,
+							spells: [
+								{
+									name: "Heal",
+									description: "You channel positive energy to heal.",
+									rank: 4,
+									usesPerDay: 3,
+								},
+								{ name: "Restoration", rank: 4 },
+							],
+						},
+					],
+				},
+			],
+		};
+
+		beforeEach(() => {
+			Object.defineProperty(globalThis, "matchMedia", {
+				writable: true,
+				configurable: true,
+				value: vi.fn().mockImplementation(() => ({
+					matches: true,
+					media: "(min-width: 1024px)",
+					onchange: null,
+					addEventListener: vi.fn(),
+					removeEventListener: vi.fn(),
+					addListener: vi.fn(),
+					removeListener: vi.fn(),
+					dispatchEvent: vi.fn(),
+				})),
+			});
+		});
+
+		it("renders a spell with a description as a clickable button", () => {
+			renderStatBlock(SPELLCASTER);
+			expect(screen.getByRole("button", { name: "Heal" })).toBeInTheDocument();
+		});
+
+		it("renders a spell without description as plain text (not a button)", () => {
+			renderStatBlock(SPELLCASTER);
+			expect(
+				screen.queryByRole("button", { name: "Restoration" }),
+			).not.toBeInTheDocument();
+			expect(screen.getByText("Restoration")).toBeInTheDocument();
+		});
+
+		it("renders usesPerDay as plain text alongside the spell button", () => {
+			renderStatBlock(SPELLCASTER);
+			expect(screen.getByText(USES_PER_DAY_REGEX)).toBeInTheDocument();
+		});
+
+		it("opens the spell popover when a spell button is clicked", async () => {
+			const user = userEvent.setup();
+			renderStatBlock(SPELLCASTER);
+			await user.click(screen.getByRole("button", { name: "Heal" }));
+			expect(screen.getByText(HEAL_DESCRIPTION_REGEX)).toBeInTheDocument();
+		});
+
+		it("closes the popover when Escape is pressed", async () => {
+			const user = userEvent.setup();
+			renderStatBlock(SPELLCASTER);
+			await user.click(screen.getByRole("button", { name: "Heal" }));
+			expect(screen.getByText(HEAL_DESCRIPTION_REGEX)).toBeInTheDocument();
+			await user.keyboard("{Escape}");
+			expect(
+				screen.queryByText(HEAL_DESCRIPTION_REGEX),
+			).not.toBeInTheDocument();
+		});
+	});
 });

apps/web/src/components/__tests__/spell-detail-popover.test.tsx

@@ -0,0 +1,158 @@
+// @vitest-environment jsdom
+import "@testing-library/jest-dom/vitest";
+
+import type { SpellReference } from "@initiative/domain";
+import { cleanup, fireEvent, render, screen } from "@testing-library/react";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { SpellDetailPopover } from "../spell-detail-popover.js";
+
+afterEach(cleanup);
+
+const FIREBALL: SpellReference = {
+	name: "Fireball",
+	slug: "fireball",
+	rank: 3,
+	description: "A spark leaps from your fingertip to the target.",
+	traits: ["fire", "manipulate"],
+	traditions: ["arcane", "primal"],
+	range: "500 feet",
+	area: "20-foot burst",
+	defense: "basic Reflex",
+	actionCost: "2",
+	heightening: "Heightened (+1) The damage increases by 2d6.",
+};
+
+const ANCHOR: DOMRect = new DOMRect(100, 100, 50, 20);
+
+const SPARK_LEAPS_REGEX = /spark leaps/;
+const HEIGHTENED_REGEX = /Heightened.*2d6/;
+const RANGE_REGEX = /500 feet/;
+const AREA_REGEX = /20-foot burst/;
+const DEFENSE_REGEX = /basic Reflex/;
+const NO_DESCRIPTION_REGEX = /No description available/;
+const DIALOG_LABEL_REGEX = /Spell details: Fireball/;
+
+beforeEach(() => {
+	// Force desktop variant in jsdom
+	Object.defineProperty(globalThis, "matchMedia", {
+		writable: true,
+		configurable: true,
+		value: vi.fn().mockImplementation(() => ({
+			matches: true,
+			media: "(min-width: 1024px)",
+			onchange: null,
+			addEventListener: vi.fn(),
+			removeEventListener: vi.fn(),
+			addListener: vi.fn(),
+			removeListener: vi.fn(),
+			dispatchEvent: vi.fn(),
+		})),
+	});
+});
+
+describe("SpellDetailPopover", () => {
+	it("renders spell name, rank, traits, and description", () => {
+		render(
+			<SpellDetailPopover
+				spell={FIREBALL}
+				anchorRect={ANCHOR}
+				onClose={() => {}}
+			/>,
+		);
+		expect(screen.getByText("Fireball")).toBeInTheDocument();
+		expect(screen.getByText("3rd")).toBeInTheDocument();
+		expect(screen.getByText("fire")).toBeInTheDocument();
+		expect(screen.getByText("manipulate")).toBeInTheDocument();
+		expect(screen.getByText(SPARK_LEAPS_REGEX)).toBeInTheDocument();
+	});
+
+	it("renders heightening rules when present", () => {
+		render(
+			<SpellDetailPopover
+				spell={FIREBALL}
+				anchorRect={ANCHOR}
+				onClose={() => {}}
+			/>,
+		);
+		expect(screen.getByText(HEIGHTENED_REGEX)).toBeInTheDocument();
+	});
+
+	it("renders range, area, and defense", () => {
+		render(
+			<SpellDetailPopover
+				spell={FIREBALL}
+				anchorRect={ANCHOR}
+				onClose={() => {}}
+			/>,
+		);
+		expect(screen.getByText(RANGE_REGEX)).toBeInTheDocument();
+		expect(screen.getByText(AREA_REGEX)).toBeInTheDocument();
+		expect(screen.getByText(DEFENSE_REGEX)).toBeInTheDocument();
+	});
+
+	it("calls onClose when Escape is pressed", () => {
+		const onClose = vi.fn();
+		render(
+			<SpellDetailPopover
+				spell={FIREBALL}
+				anchorRect={ANCHOR}
+				onClose={onClose}
+			/>,
+		);
+		fireEvent.keyDown(document, { key: "Escape" });
+		expect(onClose).toHaveBeenCalledTimes(1);
+	});
+
+	it("shows placeholder when description is missing", () => {
+		const spell: SpellReference = { name: "Mystery", rank: 1 };
+		render(
+			<SpellDetailPopover
+				spell={spell}
+				anchorRect={ANCHOR}
+				onClose={() => {}}
+			/>,
+		);
+		expect(screen.getByText(NO_DESCRIPTION_REGEX)).toBeInTheDocument();
+	});
+
+	it("renders the action cost as an icon when it is a numeric action count", () => {
+		render(
+			<SpellDetailPopover
+				spell={FIREBALL}
+				anchorRect={ANCHOR}
+				onClose={() => {}}
+			/>,
+		);
+		// Action cost "2" renders as an SVG ActivityIcon (portaled to body)
+		const dialog = screen.getByRole("dialog");
+		expect(dialog.querySelector("svg")).toBeInTheDocument();
+	});
+
+	it("renders non-numeric action cost as text", () => {
+		const spell: SpellReference = {
+			...FIREBALL,
+			actionCost: "1 minute",
+		};
+		render(
+			<SpellDetailPopover
+				spell={spell}
+				anchorRect={ANCHOR}
+				onClose={() => {}}
+			/>,
+		);
+		expect(screen.getByText("1 minute")).toBeInTheDocument();
+	});
+
+	it("uses the dialog role with the spell name as label", () => {
+		render(
+			<SpellDetailPopover
+				spell={FIREBALL}
+				anchorRect={ANCHOR}
+				onClose={() => {}}
+			/>,
+		);
+		expect(
+			screen.getByRole("dialog", { name: DIALOG_LABEL_REGEX }),
+		).toBeInTheDocument();
+	});
+});

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

@@ -111,9 +111,15 @@ const DRAGON: Creature = {
 		{
 			name: "Innate Spellcasting",
 			headerText: "The dragon's spellcasting ability is Charisma.",
-			atWill: ["detect magic", "suggestion"],
-			daily: [{ uses: 3, each: true, spells: ["fireball", "wall of fire"] }],
-			restLong: [{ uses: 1, each: false, spells: ["wish"] }],
+			atWill: [{ name: "detect magic" }, { name: "suggestion" }],
+			daily: [
+				{
+					uses: 3,
+					each: true,
+					spells: [{ name: "fireball" }, { name: "wall of fire" }],
+				},
+			],
+			restLong: [{ uses: 1, each: false, spells: [{ name: "wish" }] }],
 		},
 	],
 };

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

@@ -134,7 +134,7 @@ export function DndStatBlock({ creature }: Readonly<DndStatBlockProps>) {
 							{sc.atWill && sc.atWill.length > 0 && (
 								<div className="pl-2">
 									<span className="font-semibold">At Will:</span>{" "}
-									{sc.atWill.join(", ")}
+									{sc.atWill.map((s) => s.name).join(", ")}
 								</div>
 							)}
 							{sc.daily?.map((d) => (
@@ -143,7 +143,7 @@ export function DndStatBlock({ creature }: Readonly<DndStatBlockProps>) {
 										{d.uses}/day
 										{d.each ? " each" : ""}:
 									</span>{" "}
-									{d.spells.join(", ")}
+									{d.spells.map((s) => s.name).join(", ")}
 								</div>
 							))}
 							{sc.restLong?.map((d) => (
@@ -155,7 +155,7 @@ export function DndStatBlock({ creature }: Readonly<DndStatBlockProps>) {
 										{d.uses}/long rest
 										{d.each ? " each" : ""}:
 									</span>{" "}
-									{d.spells.join(", ")}
+									{d.spells.map((s) => s.name).join(", ")}
 								</div>
 							))}
 						</div>

apps/web/src/components/pf2e-stat-block.tsx

@@ -1,5 +1,7 @@
-import type { Pf2eCreature } from "@initiative/domain";
+import type { Pf2eCreature, SpellReference } from "@initiative/domain";
 import { formatInitiativeModifier } from "@initiative/domain";
+import { useCallback, useRef, useState } from "react";
+import { SpellDetailPopover } from "./spell-detail-popover.js";
 import {
 	PropertyLine,
 	SectionDivider,
@@ -34,7 +36,83 @@ function formatMod(mod: number): string {
 	return mod >= 0 ? `+${mod}` : `${mod}`;
 }
 
+interface SpellLinkProps {
+	readonly spell: SpellReference;
+	readonly onOpen: (spell: SpellReference, rect: DOMRect) => void;
+}
+
+function UsesPerDay({ count }: Readonly<{ count: number | undefined }>) {
+	if (count === undefined || count <= 1) return null;
+	return <span> (×{count})</span>;
+}
+
+function SpellLink({ spell, onOpen }: Readonly<SpellLinkProps>) {
+	const ref = useRef<HTMLButtonElement>(null);
+	const handleClick = useCallback(() => {
+		if (!spell.description) return;
+		const rect = ref.current?.getBoundingClientRect();
+		if (rect) onOpen(spell, rect);
+	}, [spell, onOpen]);
+
+	if (!spell.description) {
+		return (
+			<span>
+				{spell.name}
+				<UsesPerDay count={spell.usesPerDay} />
+			</span>
+		);
+	}
+
+	return (
+		<>
+			<button
+				ref={ref}
+				type="button"
+				onClick={handleClick}
+				className="cursor-pointer text-foreground underline decoration-dotted underline-offset-2 hover:text-hover-neutral"
+			>
+				{spell.name}
+			</button>
+			<UsesPerDay count={spell.usesPerDay} />
+		</>
+	);
+}
+
+interface SpellListLineProps {
+	readonly label: string;
+	readonly spells: readonly SpellReference[];
+	readonly onOpen: (spell: SpellReference, rect: DOMRect) => void;
+}
+
+function SpellListLine({
+	label,
+	spells,
+	onOpen,
+}: Readonly<SpellListLineProps>) {
+	return (
+		<div className="pl-2">
+			<span className="font-semibold">{label}:</span>{" "}
+			{spells.map((spell, i) => (
+				<span key={spell.slug ?? spell.name}>
+					{i > 0 ? ", " : ""}
+					<SpellLink spell={spell} onOpen={onOpen} />
+				</span>
+			))}
+		</div>
+	);
+}
+
 export function Pf2eStatBlock({ creature }: Readonly<Pf2eStatBlockProps>) {
+	const [openSpell, setOpenSpell] = useState<{
+		spell: SpellReference;
+		rect: DOMRect;
+	} | null>(null);
+	const handleOpenSpell = useCallback(
+		(spell: SpellReference, rect: DOMRect) => setOpenSpell({ spell, rect }),
+		[],
+	);
+	const handleCloseSpell = useCallback(() => setOpenSpell(null), []);
+
 	const abilityEntries = [
 		{ label: "Str", mod: creature.abilityMods.str },
 		{ label: "Dex", mod: creature.abilityMods.dex },
@@ -152,23 +230,31 @@ export function Pf2eStatBlock({ creature }: Readonly<Pf2eStatBlockProps>) {
 								{sc.headerText}
 							</div>
 							{sc.daily?.map((d) => (
-								<div key={d.uses} className="pl-2">
-									<span className="font-semibold">
-										{d.uses === 0 ? "Cantrips" : `Rank ${d.uses}`}:
-									</span>{" "}
-									{d.spells.join(", ")}
-								</div>
+								<SpellListLine
+									key={d.uses}
+									label={d.uses === 0 ? "Cantrips" : `Rank ${d.uses}`}
+									spells={d.spells}
+									onOpen={handleOpenSpell}
+								/>
 							))}
 							{sc.atWill && sc.atWill.length > 0 && (
-								<div className="pl-2">
-									<span className="font-semibold">Cantrips:</span>{" "}
-									{sc.atWill.join(", ")}
-								</div>
+								<SpellListLine
+									label="Cantrips"
+									spells={sc.atWill}
+									onOpen={handleOpenSpell}
+								/>
 							)}
 						</div>
 					))}
 				</>
 			)}
+			{openSpell ? (
+				<SpellDetailPopover
+					spell={openSpell.spell}
+					anchorRect={openSpell.rect}
+					onClose={handleCloseSpell}
+				/>
+			) : null}
 		</div>
 	);
 }

apps/web/src/components/spell-detail-popover.tsx

@@ -0,0 +1,296 @@
+import type { ActivityCost, SpellReference } from "@initiative/domain";
+import { useEffect, useLayoutEffect, useRef, useState } from "react";
+import { createPortal } from "react-dom";
+import { useClickOutside } from "../hooks/use-click-outside.js";
+import { useSwipeToDismissDown } from "../hooks/use-swipe-to-dismiss.js";
+import { cn } from "../lib/utils.js";
+import { ActivityIcon } from "./stat-block-parts.js";
+
+interface SpellDetailPopoverProps {
+	readonly spell: SpellReference;
+	readonly anchorRect: DOMRect;
+	readonly onClose: () => void;
+}
+
+const RANK_LABELS = [
+	"Cantrip",
+	"1st",
+	"2nd",
+	"3rd",
+	"4th",
+	"5th",
+	"6th",
+	"7th",
+	"8th",
+	"9th",
+	"10th",
+];
+
+function formatRank(rank: number | undefined): string {
+	if (rank === undefined) return "";
+	return RANK_LABELS[rank] ?? `Rank ${rank}`;
+}
+
+function parseActionCost(cost: string): ActivityCost | null {
+	if (cost === "free") return { number: 1, unit: "free" };
+	if (cost === "reaction") return { number: 1, unit: "reaction" };
+	const n = Number(cost);
+	if (n >= 1 && n <= 3) return { number: n, unit: "action" };
+	return null;
+}
+
+function SpellActionCost({ cost }: Readonly<{ cost: string | undefined }>) {
+	if (!cost) return null;
+	const activity = parseActionCost(cost);
+	if (activity) {
+		return (
+			<span className="shrink-0 text-lg">
+				<ActivityIcon activity={activity} />
+			</span>
+		);
+	}
+	return <span className="shrink-0 text-muted-foreground text-xs">{cost}</span>;
+}
+
+function SpellHeader({ spell }: Readonly<{ spell: SpellReference }>) {
+	return (
+		<div className="flex items-center justify-between gap-2">
+			<h3 className="font-bold text-lg text-stat-heading">{spell.name}</h3>
+			<SpellActionCost cost={spell.actionCost} />
+		</div>
+	);
+}
+
+function SpellTraits({ traits }: Readonly<{ traits: readonly string[] }>) {
+	if (traits.length === 0) return null;
+	return (
+		<div className="flex flex-wrap gap-1">
+			{traits.map((t) => (
+				<span
+					key={t}
+					className="rounded border border-border bg-card px-1.5 py-0.5 text-foreground text-xs"
+				>
+					{t}
+				</span>
+			))}
+		</div>
+	);
+}
+
+function LabeledValue({
+	label,
+	value,
+}: Readonly<{ label: string; value: string }>) {
+	return (
+		<>
+			<span className="font-semibold">{label}</span> {value}
+		</>
+	);
+}
+
+function SpellRangeLine({ spell }: Readonly<{ spell: SpellReference }>) {
+	const items: { label: string; value: string }[] = [];
+	if (spell.range) items.push({ label: "Range", value: spell.range });
+	if (spell.target) items.push({ label: "Target", value: spell.target });
+	if (spell.area) items.push({ label: "Area", value: spell.area });
+
+	if (items.length === 0) return null;
+	return (
+		<div>
+			{items.map((item, i) => (
+				<span key={item.label}>
+					{i > 0 ? "; " : ""}
+					<LabeledValue label={item.label} value={item.value} />
+				</span>
+			))}
+		</div>
+	);
+}
+
+function SpellMeta({ spell }: Readonly<{ spell: SpellReference }>) {
+	const hasTraditions =
+		spell.traditions !== undefined && spell.traditions.length > 0;
+	return (
+		<div className="space-y-0.5 text-xs">
+			{spell.rank === undefined ? null : (
+				<div>
+					<span className="font-semibold">{formatRank(spell.rank)}</span>
+					{hasTraditions ? (
+						<span className="text-muted-foreground">
+							{" "}
+							({spell.traditions?.join(", ")})
+						</span>
+					) : null}
+				</div>
+			)}
+			<SpellRangeLine spell={spell} />
+			{spell.duration ? (
+				<div>
+					<LabeledValue label="Duration" value={spell.duration} />
+				</div>
+			) : null}
+			{spell.defense ? (
+				<div>
+					<LabeledValue label="Defense" value={spell.defense} />
+				</div>
+			) : null}
+		</div>
+	);
+}
+
+const SAVE_OUTCOME_REGEX =
+	/(Critical Success|Critical Failure|Success|Failure)/g;
+
+function SpellDescription({ text }: Readonly<{ text: string }>) {
+	const parts = text.split(SAVE_OUTCOME_REGEX);
+	const elements: React.ReactNode[] = [];
+	let offset = 0;
+	for (const part of parts) {
+		if (SAVE_OUTCOME_REGEX.test(part)) {
+			elements.push(<strong key={`b-${offset}`}>{part}</strong>);
+		} else if (part) {
+			elements.push(<span key={`t-${offset}`}>{part}</span>);
+		}
+		offset += part.length;
+	}
+	return <p className="whitespace-pre-line text-foreground">{elements}</p>;
+}
+
+function SpellDetailContent({ spell }: Readonly<{ spell: SpellReference }>) {
+	return (
+		<div className="space-y-2 text-sm">
+			<SpellHeader spell={spell} />
+			<SpellTraits traits={spell.traits ?? []} />
+			<SpellMeta spell={spell} />
+			{spell.description ? (
+				<SpellDescription text={spell.description} />
+			) : (
+				<p className="text-muted-foreground italic">
+					No description available.
+				</p>
+			)}
+			{spell.heightening ? (
+				<p className="whitespace-pre-line text-foreground text-xs">
+					{spell.heightening}
+				</p>
+			) : null}
+		</div>
+	);
+}
+
+function DesktopPopover({
+	spell,
+	anchorRect,
+	onClose,
+}: Readonly<SpellDetailPopoverProps>) {
+	const ref = useRef<HTMLDivElement>(null);
+	const [pos, setPos] = useState<{ top: number; left: number } | null>(null);
+
+	useLayoutEffect(() => {
+		const el = ref.current;
+		if (!el) return;
+		const popover = el.getBoundingClientRect();
+		const vw = document.documentElement.clientWidth;
+		const vh = document.documentElement.clientHeight;
+		// Prefer placement to the LEFT of the anchor (panel is on the right edge)
+		let left = anchorRect.left - popover.width - 8;
+		if (left < 8) {
+			left = anchorRect.right + 8;
+		}
+		if (left + popover.width > vw - 8) {
+			left = vw - popover.width - 8;
+		}
+		let top = anchorRect.top;
+		if (top + popover.height > vh - 8) {
+			top = vh - popover.height - 8;
+		}
+		if (top < 8) top = 8;
+		setPos({ top, left });
+	}, [anchorRect]);
+
+	useClickOutside(ref, onClose);
+
+	return (
+		<div
+			ref={ref}
+			className="card-glow fixed z-50 max-h-[calc(100vh-16px)] w-80 max-w-[calc(100vw-16px)] overflow-y-auto rounded-lg border border-border bg-card p-4 shadow-lg"
+			style={pos ? { top: pos.top, left: pos.left } : { visibility: "hidden" }}
+			role="dialog"
+			aria-label={`Spell details: ${spell.name}`}
+		>
+			<SpellDetailContent spell={spell} />
+		</div>
+	);
+}
+
+function MobileSheet({
+	spell,
+	onClose,
+}: Readonly<{ spell: SpellReference; onClose: () => void }>) {
+	const { offsetY, isSwiping, handlers } = useSwipeToDismissDown(onClose);
+
+	useEffect(() => {
+		const handler = (e: KeyboardEvent) => {
+			if (e.key === "Escape") onClose();
+		};
+		document.addEventListener("keydown", handler);
+		return () => document.removeEventListener("keydown", handler);
+	}, [onClose]);
+
+	return (
+		<div className="fixed inset-0 z-50">
+			<button
+				type="button"
+				className="fade-in absolute inset-0 animate-in bg-black/50"
+				onClick={onClose}
+				aria-label="Close spell details"
+			/>
+			<div
+				className={cn(
+					"panel-glow absolute right-0 bottom-0 left-0 max-h-[80vh] rounded-t-2xl border-border border-t bg-card",
+					!isSwiping && "animate-slide-in-bottom",
+				)}
+				style={
+					isSwiping ? { transform: `translateY(${offsetY}px)` } : undefined
+				}
+				{...handlers}
+				role="dialog"
+				aria-label={`Spell details: ${spell.name}`}
+			>
+				<div className="flex justify-center pt-2 pb-1">
+					<div className="h-1 w-10 rounded-full bg-muted-foreground/40" />
+				</div>
+				<div className="max-h-[calc(80vh-24px)] overflow-y-auto p-4">
+					<SpellDetailContent spell={spell} />
+				</div>
+			</div>
+		</div>
+	);
+}
+
+export function SpellDetailPopover({
+	spell,
+	anchorRect,
+	onClose,
+}: Readonly<SpellDetailPopoverProps>) {
+	const [isDesktop, setIsDesktop] = useState(
+		() => globalThis.matchMedia("(min-width: 1024px)").matches,
+	);
+
+	useEffect(() => {
+		const mq = globalThis.matchMedia("(min-width: 1024px)");
+		const handler = (e: MediaQueryListEvent) => setIsDesktop(e.matches);
+		mq.addEventListener("change", handler);
+		return () => mq.removeEventListener("change", handler);
+	}, []);
+
+	// Portal to document.body to escape any CSS transforms on ancestors
+	// (the side panel uses translate-x for collapse animation, which would
+	// otherwise become the containing block for fixed-positioned children).
+	const content = isDesktop ? (
+		<DesktopPopover spell={spell} anchorRect={anchorRect} onClose={onClose} />
+	) : (
+		<MobileSheet spell={spell} onClose={onClose} />
+	);
+	return createPortal(content, document.body);
+}

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

@@ -71,7 +71,9 @@ const FREE_ACTION_CHEVRON = "M48 27 L71 50 L48 73 Z";
 const REACTION_ARROW =
 	"M75 15 A42 42 0 1 0 85 55 L72 55 A30 30 0 1 1 65 25 L65 40 L92 20 L65 0 L65 15 Z";
 
-function ActivityIcon({ activity }: Readonly<{ activity: ActivityCost }>) {
+export function ActivityIcon({
+	activity,
+}: Readonly<{ activity: ActivityCost }>) {
 	const cls = "inline-block h-[1em] align-[-0.1em]";
 	if (activity.unit === "free") {
 		return (