feat(ui): extend design tokens, add dark mode, add UI primitives

- Add warning/success token roles across light and dark themes
- Add Light/Dark/System theme mode (localStorage + Appwrite prefs)
- Derive dark token stacks from existing theme seeds
- Remove forced light app-shell background; dynamic color-scheme
- Add Button/Card/Field/Badge/EmptyState primitives under src/components/ui

src/App.tsx

@@ -61,11 +61,16 @@ import {
 import { BUILT_IN_FLAVOURS, DEFAULT_FLAVOUR, accentForCustomFlavour, flavourMeta, mergedFlavours } from "./data/flavours";
 import {
   APP_THEMES,
+  THEME_MODE_STORAGE_KEY,
   THEME_STORAGE_KEY,
   getThemeById,
+  getThemeTokens,
   normaliseThemeId,
+  normaliseThemeMode,
   readStoredThemeId,
+  readStoredThemeMode,
   type AppTheme,
+  type ThemeMode,
 } from "./data/themes";
 import { themeTokensToStyle } from "./lib/themeTokens";
 import { account, appwriteConfig, Channel, client, pingAppwrite } from "./lib/appwrite";
@@ -178,10 +183,21 @@ const NAV_ITEMS: Array<{ id: AppView; label: string; icon: LucideIcon }> = [
   { id: "settings", label: "Settings", icon: Settings2 },
 ];
 
+const THEME_MODES: Array<{ id: ThemeMode; label: string }> = [
+  { id: "light", label: "Light" },
+  { id: "dark", label: "Dark" },
+  { id: "system", label: "System" },
+];
+
 function App() {
   const [themeId, setThemeId] = useState(() => readStoredThemeId());
+  const [themeMode, setThemeMode] = useState<ThemeMode>(() => readStoredThemeMode());
+  const [systemDark, setSystemDark] = useState(
+    () => typeof window !== "undefined" && window.matchMedia("(prefers-color-scheme: dark)").matches,
+  );
   const activeTheme = useMemo(() => getThemeById(themeId), [themeId]);
-  const shellStyle = useMemo(() => themeTokensToStyle(activeTheme.tokens), [activeTheme]);
+  const resolvedMode: "light" | "dark" = themeMode === "system" ? (systemDark ? "dark" : "light") : themeMode;
+  const shellStyle = useMemo(() => themeTokensToStyle(getThemeTokens(themeId, resolvedMode)), [themeId, resolvedMode]);
   const [user, setUser] = useState<AuthUser | null>(null);
   const [authLoading, setAuthLoading] = useState(true);
   const [authError, setAuthError] = useState("");
@@ -214,6 +230,19 @@ function App() {
     localStorage.setItem(THEME_STORAGE_KEY, normaliseThemeId(themeId));
   }, [themeId]);
 
+  useEffect(() => {
+    localStorage.setItem(THEME_MODE_STORAGE_KEY, themeMode);
+  }, [themeMode]);
+
+  useEffect(() => {
+    if (typeof window === "undefined") return undefined;
+    const media = window.matchMedia("(prefers-color-scheme: dark)");
+    const handleChange = (event: MediaQueryListEvent) => setSystemDark(event.matches);
+    setSystemDark(media.matches);
+    media.addEventListener("change", handleChange);
+    return () => media.removeEventListener("change", handleChange);
+  }, []);
+
   const refreshEntries = useCallback(async (userId: string, showLoader = true) => {
     if (showLoader) setDataLoading(true);
     setSyncError("");
@@ -256,6 +285,9 @@ function App() {
         if (typeof currentUser.prefs.themeId === "string" && currentUser.prefs.themeId) {
           setThemeId(normaliseThemeId(currentUser.prefs.themeId));
         }
+        if (typeof currentUser.prefs.themeMode === "string" && currentUser.prefs.themeMode) {
+          setThemeMode(normaliseThemeMode(currentUser.prefs.themeMode));
+        }
         setNotice(`Signed in as ${currentUser.email || currentUser.name || "Appwrite user"}.`);
         if (!currentUser.prefs.onboarded) {
           setSetupOpen(true);
@@ -325,6 +357,9 @@ function App() {
       if (typeof currentUser.prefs.themeId === "string" && currentUser.prefs.themeId) {
         setThemeId(normaliseThemeId(currentUser.prefs.themeId));
       }
+      if (typeof currentUser.prefs.themeMode === "string" && currentUser.prefs.themeMode) {
+        setThemeMode(normaliseThemeMode(currentUser.prefs.themeMode));
+      }
       setNotice(`Signed in as ${currentUser.email}.`);
       if (!currentUser.prefs.onboarded) {
         setSetupOpen(true);
@@ -422,6 +457,7 @@ function App() {
       const nextPrefs = {
         ...limitsPrefs,
         themeId: onboardingThemeId,
+        themeMode,
         onboarded: true,
       };
       await account.updatePrefs(nextPrefs);
@@ -627,7 +663,7 @@ function App() {
   }
 
   if (authLoading) {
-    return <LoadingScreen setupStatus={setupStatus} shellStyle={shellStyle} themeId={themeId} />;
+    return <LoadingScreen setupStatus={setupStatus} shellStyle={shellStyle} themeId={themeId} resolvedMode={resolvedMode} />;
   }
 
   if (!user) {
@@ -638,6 +674,7 @@ function App() {
         setupStatus={setupStatus}
         shellStyle={shellStyle}
         themeId={themeId}
+        resolvedMode={resolvedMode}
         onLogin={login}
         onSignup={signup}
       />
@@ -648,6 +685,7 @@ function App() {
     <div
       className="app-shell min-h-screen overflow-x-hidden"
       data-theme={themeId}
+      data-mode={resolvedMode}
       style={shellStyle}
     >
       {setupOpen && user && (
@@ -770,6 +808,7 @@ function App() {
                   notice={notice}
                   setupStatus={setupStatus}
                   themeId={themeId}
+                  themeMode={themeMode}
                   user={user}
                   userLimits={userLimits}
                   limitCheck={limitCheck}
@@ -781,6 +820,7 @@ function App() {
                   onLogout={() => void logout()}
                   onReset={() => setIsResetOpen(true)}
                   onThemeChange={setThemeId}
+                  onThemeModeChange={setThemeMode}
                   onSaveLimits={(next) => void saveUserLimits(next)}
                   onRerunOnboarding={() => setSetupOpen(true)}
                 />
@@ -864,13 +904,15 @@ function LoadingScreen({
   setupStatus,
   shellStyle,
   themeId,
+  resolvedMode,
 }: {
   setupStatus: SetupStatus;
   shellStyle: CSSProperties;
   themeId: string;
+  resolvedMode: "light" | "dark";
 }) {
   return (
-    <div className="app-shell min-h-screen" data-theme={themeId} style={shellStyle}>
+    <div className="app-shell min-h-screen" data-theme={themeId} data-mode={resolvedMode} style={shellStyle}>
       <ShellBackdrop />
       <div className="flex min-h-screen items-center justify-center p-6">
         <div className="glass-panel w-full max-w-md p-6 text-center">
@@ -891,6 +933,7 @@ function AuthView({
   setupStatus,
   shellStyle,
   themeId,
+  resolvedMode,
   onLogin,
   onSignup,
 }: {
@@ -899,6 +942,7 @@ function AuthView({
   setupStatus: SetupStatus;
   shellStyle: CSSProperties;
   themeId: string;
+  resolvedMode: "light" | "dark";
   onLogin: (email: string, password: string) => Promise<void>;
   onSignup: (name: string, email: string, password: string) => Promise<void>;
 }) {
@@ -917,7 +961,7 @@ function AuthView({
   }
 
   return (
-    <div className="app-shell min-h-screen" data-theme={themeId} style={shellStyle}>
+    <div className="app-shell min-h-screen" data-theme={themeId} data-mode={resolvedMode} style={shellStyle}>
       <ShellBackdrop />
       <main className="flex min-h-screen items-center justify-center p-6">
         <div className="auth-panel-shell">
@@ -980,15 +1024,38 @@ function AuthView({
 
 function ThemePicker({
   themeId,
+  themeMode,
   onChange,
+  onThemeModeChange,
 }: {
   themeId: string;
+  themeMode: ThemeMode;
   onChange: (id: string) => void;
+  onThemeModeChange: (mode: ThemeMode) => void;
 }) {
   const activeTheme = getThemeById(themeId);
 
   return (
     <div className="settings-section">
+      <div
+        className="segmented-control max-w-xs"
+        role="group"
+        aria-label="Colour mode"
+        style={{ gridTemplateColumns: "repeat(3, minmax(0, 1fr))" }}
+      >
+        {THEME_MODES.map((mode) => (
+          <button
+            key={mode.id}
+            type="button"
+            aria-pressed={themeMode === mode.id}
+            className={themeMode === mode.id ? "segmented-control-active" : ""}
+            onClick={() => onThemeModeChange(mode.id)}
+          >
+            {mode.label}
+          </button>
+        ))}
+      </div>
+
       <div className="theme-preview-strip">
         <div className="theme-preview-chip primary-button px-4 py-2 text-sm">Button</div>
         <div className="theme-preview-chip glass-panel px-4 py-2 text-sm">Panel</div>
@@ -1884,6 +1951,7 @@ function SettingsView({
   notice,
   setupStatus,
   themeId,
+  themeMode,
   user,
   userLimits,
   limitCheck,
@@ -1895,6 +1963,7 @@ function SettingsView({
   onLogout,
   onReset,
   onThemeChange,
+  onThemeModeChange,
   onSaveLimits,
   onRerunOnboarding,
 }: {
@@ -1905,6 +1974,7 @@ function SettingsView({
   notice: string;
   setupStatus: SetupStatus;
   themeId: string;
+  themeMode: ThemeMode;
   user: AuthUser | null;
   userLimits: UserLimits;
   limitCheck: LimitCheckResult;
@@ -1916,6 +1986,7 @@ function SettingsView({
   onLogout: () => void;
   onReset: () => void;
   onThemeChange: (id: string) => void;
+  onThemeModeChange: (mode: ThemeMode) => void;
   onSaveLimits: (limits: UserLimits) => void;
   onRerunOnboarding: () => void;
 }) {
@@ -1942,7 +2013,7 @@ function SettingsView({
         </AppCard>
 
         <AppCard title="Appearance" subtitle={`${activeTheme.label} theme active`}>
-          <ThemePicker themeId={themeId} onChange={onThemeChange} />
+          <ThemePicker themeId={themeId} themeMode={themeMode} onChange={onThemeChange} onThemeModeChange={onThemeModeChange} />
         </AppCard>
 
         <AppCard title="Data & sync" subtitle={`${entries.length} entries synced for this user`}>

src/components/ui/Badge.tsx

@@ -0,0 +1,17 @@
+import type { HTMLAttributes, ReactNode } from "react";
+
+export type BadgeTone = "neutral" | "accent" | "success" | "warning" | "danger";
+
+export type BadgeProps = {
+  tone?: BadgeTone;
+  children: ReactNode;
+} & HTMLAttributes<HTMLSpanElement>;
+
+export function Badge({ tone = "neutral", className, children, ...rest }: BadgeProps) {
+  const classes = ["badge", tone !== "neutral" ? `badge-${tone}` : "", className].filter(Boolean).join(" ");
+  return (
+    <span className={classes} {...rest}>
+      {children}
+    </span>
+  );
+}

src/components/ui/Button.tsx

@@ -0,0 +1,35 @@
+import { Loader2 } from "lucide-react";
+import type { ButtonHTMLAttributes, ReactNode } from "react";
+
+export type ButtonVariant = "primary" | "secondary" | "danger";
+
+export type ButtonProps = {
+  variant?: ButtonVariant;
+  loading?: boolean;
+  icon?: ReactNode;
+} & ButtonHTMLAttributes<HTMLButtonElement>;
+
+const BUTTON_VARIANT_CLASSES: Record<ButtonVariant, string> = {
+  primary: "primary-button",
+  secondary: "secondary-button",
+  danger: "danger-button",
+};
+
+export function Button({
+  variant = "primary",
+  loading = false,
+  icon,
+  className,
+  children,
+  disabled,
+  type = "button",
+  ...rest
+}: ButtonProps) {
+  const classes = [BUTTON_VARIANT_CLASSES[variant], className].filter(Boolean).join(" ");
+  return (
+    <button className={classes} type={type} disabled={disabled || loading} aria-busy={loading || undefined} {...rest}>
+      {loading ? <Loader2 className="animate-spin" size={17} aria-hidden="true" /> : icon}
+      {children}
+    </button>
+  );
+}

src/components/ui/Card.tsx

@@ -0,0 +1,27 @@
+import type { ReactNode } from "react";
+
+export type CardProps = {
+  title?: string;
+  subtitle?: string;
+  actions?: ReactNode;
+  className?: string;
+  children: ReactNode;
+};
+
+export function Card({ title, subtitle, actions, className, children }: CardProps) {
+  const classes = ["app-card p-4 sm:p-5", className].filter(Boolean).join(" ");
+  return (
+    <section className={classes}>
+      {(title || subtitle || actions) && (
+        <div className="mb-4 flex items-start justify-between gap-3">
+          <div className="min-w-0">
+            {title && <h2 className="app-card-title text-xl">{title}</h2>}
+            {subtitle && <p className="app-card-subtitle mt-1">{subtitle}</p>}
+          </div>
+          {actions && <div className="flex shrink-0 items-center gap-2">{actions}</div>}
+        </div>
+      )}
+      {children}
+    </section>
+  );
+}

src/components/ui/EmptyState.tsx

@@ -0,0 +1,22 @@
+import { Zap } from "lucide-react";
+import type { ReactNode } from "react";
+
+export type EmptyStateProps = {
+  icon?: ReactNode;
+  title: string;
+  body: string;
+  action?: ReactNode;
+  className?: string;
+};
+
+export function EmptyState({ icon, title, body, action, className }: EmptyStateProps) {
+  const classes = ["empty-state", className].filter(Boolean).join(" ");
+  return (
+    <div className={classes}>
+      <div className="empty-state-icon">{icon ?? <Zap size={22} aria-hidden="true" />}</div>
+      <h3 className="empty-state-title">{title}</h3>
+      <p className="empty-state-copy mt-2 max-w-sm">{body}</p>
+      {action && <div className="mt-4">{action}</div>}
+    </div>
+  );
+}

src/components/ui/Field.tsx

@@ -0,0 +1,40 @@
+import type { ReactNode } from "react";
+
+export type FieldControlProps = {
+  id: string;
+  "aria-invalid": true | undefined;
+  "aria-describedby": string | undefined;
+};
+
+export type FieldProps = {
+  id: string;
+  label: string;
+  error?: string;
+  help?: string;
+  className?: string;
+  children: (controlProps: FieldControlProps) => ReactNode;
+};
+
+export function Field({ id, label, error, help, className, children }: FieldProps) {
+  const message = error ?? help;
+  const messageId = message ? `${id}-message` : undefined;
+  return (
+    <div className={className}>
+      <label className="field-label" htmlFor={id}>
+        {label}
+      </label>
+      <div className="mt-2">
+        {children({
+          id,
+          "aria-invalid": error ? true : undefined,
+          "aria-describedby": messageId,
+        })}
+      </div>
+      {message && (
+        <p id={messageId} className={error ? "field-error-text" : "field-help-text"}>
+          {message}
+        </p>
+      )}
+    </div>
+  );
+}

src/components/ui/index.ts

@@ -0,0 +1,10 @@
+export { Badge } from "./Badge";
+export type { BadgeProps, BadgeTone } from "./Badge";
+export { Button } from "./Button";
+export type { ButtonProps, ButtonVariant } from "./Button";
+export { Card } from "./Card";
+export type { CardProps } from "./Card";
+export { EmptyState } from "./EmptyState";
+export type { EmptyStateProps } from "./EmptyState";
+export { Field } from "./Field";
+export type { FieldControlProps, FieldProps } from "./Field";

src/data/themes.ts

@@ -4,12 +4,16 @@ export type AppTheme = {
   id: string;
   label: string;
   swatch: string;
+  seed: ThemeSeed;
   tokens: ThemeTokens;
 };
 
+export type ThemeMode = "light" | "dark" | "system";
+
 export const THEME_STORAGE_KEY = "red-bull-intake-tracker.theme.v2";
 export const OLD_THEME_STORAGE_KEY = "red-bull-intake-tracker.theme.v1";
 export const LEGACY_ACCENT_STORAGE_KEY = "red-bull-intake-tracker.accent.v1";
+export const THEME_MODE_STORAGE_KEY = "red-bull-intake-tracker.theme-mode.v1";
 export const DEFAULT_THEME_ID = "mist";
 
 const OLD_THEME_MAP: Record<string, string> = {
@@ -50,7 +54,7 @@ const OLD_THEME_MAP: Record<string, string> = {
 };
 
 function theme(id: string, label: string, swatch: string, seed: ThemeSeed): AppTheme {
-  return { id, label, swatch, tokens: buildThemeTokens(seed) };
+  return { id, label, swatch, seed, tokens: buildThemeTokens(seed) };
 }
 
 export const APP_THEMES: AppTheme[] = [
@@ -97,6 +101,30 @@ export function getThemeById(id: string): AppTheme {
   return APP_THEMES.find((entry) => entry.id === id) ?? APP_THEMES[0];
 }
 
+export function getThemeTokens(id: string, mode: "light" | "dark"): ThemeTokens {
+  const entry = getThemeById(id);
+  if (mode === "light") return entry.tokens;
+
+  // Dark mode drops the light-only explicit overrides; chart colours that
+  // still read well on dark surfaces are carried over.
+  const overrides = entry.seed.tokens;
+  const chartOverrides: Partial<ThemeTokens> = {};
+  if (overrides?.chartPrimary) chartOverrides.chartPrimary = overrides.chartPrimary;
+  if (overrides?.chartSecondary) chartOverrides.chartSecondary = overrides.chartSecondary;
+  if (overrides?.chartTertiary) chartOverrides.chartTertiary = overrides.chartTertiary;
+  return buildThemeTokens({ ...entry.seed, dark: true, tokens: chartOverrides });
+}
+
+export function normaliseThemeMode(value: string | null | undefined): ThemeMode {
+  if (value === "light" || value === "dark" || value === "system") return value;
+  return "system";
+}
+
+export function readStoredThemeMode(): ThemeMode {
+  if (typeof window === "undefined") return "system";
+  return normaliseThemeMode(localStorage.getItem(THEME_MODE_STORAGE_KEY));
+}
+
 export function normaliseThemeId(id: string | null | undefined): string {
   if (!id) return DEFAULT_THEME_ID;
   if (APP_THEMES.some((entry) => entry.id === id)) return id;

src/index.css

@@ -3,7 +3,9 @@
 @tailwind utilities;
 
 :root {
-  color-scheme: light;
+  --radius-sm: 10px;
+  --radius-md: 14px;
+  --radius-lg: 20px;
   font-family: "Google Sans", "SF Pro Display", Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
   background: #eef3fb;
 }
@@ -76,10 +78,15 @@ textarea:focus-visible {
 
 .app-shell {
   min-height: 100vh;
+  color: var(--text, #202124);
   background:
     radial-gradient(circle at 78% 12%, color-mix(in srgb, var(--primary-container, #dbe9ff) 42%, transparent), transparent 32rem),
-    #eef3fb !important;
+    var(--bg, #eef3fb);
-  color: #202124 !important;
+  color-scheme: light;
+}
+
+.app-shell[data-mode="dark"] {
+  color-scheme: dark;
 }
 
 .app-layout {
@@ -996,6 +1003,21 @@ textarea:focus-visible {
   color: #80868b;
 }
 
+.field-help-text,
+.field-error-text {
+  margin-top: 6px;
+  font-size: 13px;
+  line-height: 1.4;
+}
+
+.field-help-text {
+  color: var(--muted, #5f6670);
+}
+
+.field-error-text {
+  color: var(--error, #ba1a1a);
+}
+
 .entry-row {
   display: grid;
   gap: 12px;
@@ -1085,6 +1107,45 @@ textarea:focus-visible {
   border-radius: 999px;
 }
 
+.badge {
+  display: inline-flex;
+  min-height: 26px;
+  align-items: center;
+  gap: 6px;
+  padding: 0 10px;
+  color: var(--muted, #5f6670);
+  background: var(--surface-container-high, #f1f4f9);
+  border: 1px solid var(--outline-variant, #dce5f1);
+  border-radius: 999px;
+  font-size: 12px;
+  font-weight: 500;
+  line-height: 1;
+}
+
+.badge-accent {
+  color: var(--on-primary-container, #10243f);
+  background: var(--primary-container, #dbe9ff);
+  border-color: color-mix(in srgb, var(--primary, #2563c7) 24%, transparent);
+}
+
+.badge-success {
+  color: var(--on-success-container, #03210f);
+  background: var(--success-container, #ceead6);
+  border-color: color-mix(in srgb, var(--success, #0d652d) 24%, transparent);
+}
+
+.badge-warning {
+  color: var(--on-warning-container, #291800);
+  background: var(--warning-container, #ffddb0);
+  border-color: color-mix(in srgb, var(--warning, #8d5700) 24%, transparent);
+}
+
+.badge-danger {
+  color: var(--on-error-container, #410002);
+  background: var(--error-container, #ffdad6);
+  border-color: color-mix(in srgb, var(--error, #ba1a1a) 24%, transparent);
+}
+
 .segmented-control {
   display: grid;
   grid-template-columns: repeat(4, minmax(0, 1fr));

src/lib/themeTokens.ts

@@ -17,6 +17,14 @@ export type ThemeTokens = {
   onError: string;
   errorContainer: string;
   onErrorContainer: string;
+  warning: string;
+  onWarning: string;
+  warningContainer: string;
+  onWarningContainer: string;
+  success: string;
+  onSuccess: string;
+  successContainer: string;
+  onSuccessContainer: string;
   bg: string;
   surface: string;
   surfaceContainerLowest: string;
@@ -160,6 +168,10 @@ export function buildThemeTokens(seed: ThemeSeed): ThemeTokens {
   const tertiaryContainer = containerColor(tertiary);
   const error = "#ba1a1a";
   const errorContainer = "#ffdad6";
+  const warning = dark ? "#fbbc04" : "#8d5700";
+  const warningContainer = dark ? "#594400" : "#ffddb0";
+  const success = dark ? "#81c995" : "#0d652d";
+  const successContainer = dark ? "#0f5223" : "#ceead6";
 
   const tokens: ThemeTokens = {
     primary,
@@ -178,6 +190,14 @@ export function buildThemeTokens(seed: ThemeSeed): ThemeTokens {
     onError: "#ffffff",
     errorContainer,
     onErrorContainer: "#410002",
+    warning,
+    onWarning: dark ? "#3a2a00" : "#ffffff",
+    warningContainer,
+    onWarningContainer: dark ? "#ffe1a6" : "#291800",
+    success,
+    onSuccess: dark ? "#07391c" : "#ffffff",
+    successContainer,
+    onSuccessContainer: dark ? "#ceead6" : "#03210f",
     bg: surfaces.bg,
     surface: surfaces.surface,
     surfaceContainerLowest: surfaces.surfaceContainerLowest,
@@ -220,6 +240,14 @@ export function themeTokensToStyle(tokens: ThemeTokens): CSSProperties {
     "--on-error": tokens.onError,
     "--error-container": tokens.errorContainer,
     "--on-error-container": tokens.onErrorContainer,
+    "--warning": tokens.warning,
+    "--on-warning": tokens.onWarning,
+    "--warning-container": tokens.warningContainer,
+    "--on-warning-container": tokens.onWarningContainer,
+    "--success": tokens.success,
+    "--on-success": tokens.onSuccess,
+    "--success-container": tokens.successContainer,
+    "--on-success-container": tokens.onSuccessContainer,
     "--bg": tokens.bg,
     "--surface": tokens.surface,
     "--surface-container-lowest": tokens.surfaceContainerLowest,