refactor(web): move styles into per-component CSS modules

.gitignore

@@ -1,6 +1,7 @@
 # Dependencies and build output
 node_modules/
 dist/
+storybook-static/
 coverage/
 *.tsbuildinfo
 .cache/
@@ -31,3 +32,6 @@ test-results/
 .DS_Store
 .claude/
 .amp/
+
+# Generated from each CSS module by `bun run --cwd apps/web css-types`
+*.module.css.d.ts

apps/web/.storybook/main.ts

@@ -0,0 +1,8 @@
+import { defineMain } from "@storybook/react-vite/node";
+
+// Storybook reads apps/web/vite.config.ts, so stories build with the same
+// plugins the interface does.
+export default defineMain({
+  framework: "@storybook/react-vite",
+  stories: ["../src/**/*.stories.tsx"],
+});

apps/web/.storybook/preview.tsx

@@ -0,0 +1,55 @@
+import { useEffect, type ReactNode } from "react";
+import { ThemeProvider, useTheme } from "@corbits/react-ui";
+import type { Preview } from "@storybook/react-vite";
+import { Toaster } from "sonner";
+// The same order main.tsx imports them in: the library's sheet, then ours.
+import "@corbits/react-ui/styles.css";
+import "../src/styles.css";
+
+type Mode = "light" | "dark";
+
+// Follows the toolbar instead of the stored preference, so a story renders
+// in the mode the reviewer picked.
+function Mode({ mode, children }: { mode: Mode; children: ReactNode }) {
+  const { setMode, resolvedMode } = useTheme();
+  useEffect(() => setMode(mode), [mode, setMode]);
+  return (
+    <>
+      {children}
+      <Toaster theme={resolvedMode} richColors closeButton />
+    </>
+  );
+}
+
+const preview: Preview = {
+  globalTypes: {
+    mode: {
+      description: "Light or dark theme",
+      toolbar: {
+        title: "Theme",
+        icon: "mirror",
+        items: [
+          { value: "light", title: "Light" },
+          { value: "dark", title: "Dark" },
+        ],
+        dynamicTitle: true,
+      },
+    },
+  },
+  initialGlobals: { mode: "light" },
+  decorators: [
+    (Story, context) => (
+      <ThemeProvider storageKey="builder-storybook-theme" defaultMode="light">
+        <Mode mode={context.globals["mode"] === "dark" ? "dark" : "light"}>
+          <Story />
+        </Mode>
+      </ThemeProvider>
+    ),
+  ],
+  parameters: {
+    layout: "padded",
+    controls: { expanded: true },
+  },
+};
+
+export default preview;

apps/web/AGENTS.md

@@ -18,6 +18,31 @@ like what is already there, and extends it rather than standing beside it.
   maintainers decide whether it moves.
 - Wording lives in the interface's config.
 
+## Styles
+
+- A component's styles live in a CSS module beside it (`pane-bar.tsx`,
+  `pane-bar.module.css`), imported as `styles`, with camelCase class names.
+  `styles.css` holds only what is global: fonts, tokens, element defaults,
+  overrides of the library that apply everywhere, and shared keyframes.
+- Each module has exact types, generated by `bun run css-types` (the `dev`
+  script keeps them current and `typecheck` regenerates them), so
+  `styles.pane` is a `string` and a misspelt class is a type error. Join
+  classes with `clsx` only when one is conditional.
+- A look used in more than one place is a component, such as `InlineNote`,
+  `Field`, `Fault` or `Banner`, not a class two components share. Shared
+  components live in `components.tsx`, or in a file of their own when they
+  belong to one area.
+- A shared component owns its whole look and takes no `className`. Variants
+  are props, rendered as `data-*` attributes (`data-tone="error"`, or an
+  empty `data-pill=""` for a flag); the element it renders is an `as` prop.
+- Every shared component's root carries a `data-slot` naming it. A parent
+  positions it from its own module through that attribute, such as
+  `.notes > [data-slot="inline-note"]` for margin, size or placement, never
+  through another module's class, and never by restyling its inside.
+- The library's own classes, such as `.dark`, go in `:global(...)`, and a
+  global keyframe in `global(...)`: `animation: global(fade-in) 200ms`.
+- Code and tests find elements by `data-*` attributes, never by a class name.
+
 ## Every artifact kind is a first-class document
 
 A new kind (a sheet, a deck, a diagram) is integrated everywhere a document

apps/web/package.json

@@ -7,8 +7,13 @@
   "author": "Sawyer Cutler <sawyer@dirtroad.dev>",
   "type": "module",
   "scripts": {
-    "dev": "vite",
-    "build": "vite build"
+    "dev": "bun run --parallel css-types:watch serve",
+    "serve": "vite",
+    "build": "vite build",
+    "css-types": "tcm -s -p \"src/**/*.module.css\"",
+    "css-types:watch": "tcm -s -w -p \"src/**/*.module.css\"",
+    "storybook": "storybook dev -p 6006",
+    "build-storybook": "storybook build -o storybook-static"
   },
   "dependencies": {
     "@corbits-builder/client": "workspace:*",
@@ -23,6 +28,7 @@
     "@tanstack/react-query": "5.104.1",
     "@tanstack/react-query-persist-client": "5.104.1",
     "arktype": "catalog:",
+    "clsx": "2.1.1",
     "diff": "9.0.0",
     "idb-keyval": "6.2.2",
     "jszip": "3.10.2",
@@ -32,9 +38,12 @@
     "sonner": "2.0.8"
   },
   "devDependencies": {
+    "@storybook/react-vite": "11.0.0-beta.0",
     "@types/react": "19.3.0",
     "@types/react-dom": "19.3.0",
     "@vitejs/plugin-react": "5.2.0",
+    "storybook": "11.0.0-beta.0",
+    "typed-css-modules": "0.9.1",
     "typescript": "5.9.3",
     "vite": "6.4.5"
   }