theme draft 1

2026-03-22 13:05:00 -04:00
parent 63ad73755d
commit d38392ac9a
18 changed files with 678 additions and 209 deletions
--- a/frontend/AGENTS.md
+++ b/frontend/AGENTS.md
@@ -20,6 +20,8 @@ Also follow the repository root guide at `../AGENTS.md`.
 - Avoid custom class names in JSX `className` values unless the Tailwind lint config already allows them.
 - For decorative icons in inputs or labels, disable hover styling via the icon component API rather than overriding it ad hoc.
 - Prefer `LoadingState` for result-area loading indicators; avoid early returns that unmount search/filter forms during fetches.
+- Use theme tokens from `tailwind.config.js` / `src/index.css` (`bg-surface`, `text-content`, `border-border`, `primary`, etc.) for new UI work instead of adding raw light/dark color pairs.
+- Store frontend-only preferences in `src/utils/localSettings.ts` so appearance and view settings share one local-storage shape.

 ## 3) Generated API client

--- a/frontend/src/components/Button.tsx
+++ b/frontend/src/components/Button.tsx
@@ -11,13 +11,13 @@ type LinkProps = BaseButtonProps & AnchorHTMLAttributes<HTMLAnchorElement> & { h

 const getVariantClasses = (variant: 'default' | 'secondary' = 'default'): string => {
  const baseClass =
-    'transition duration-100 ease-in font-medium w-full h-full px-2 py-1 text-white disabled:cursor-not-allowed disabled:opacity-50';
+    'h-full w-full px-2 py-1 font-medium transition duration-100 ease-in disabled:cursor-not-allowed disabled:opacity-50';

  if (variant === 'secondary') {
-    return `${baseClass} bg-black shadow-md hover:text-black hover:bg-white disabled:hover:text-white disabled:hover:bg-black`;
+    return `${baseClass} bg-content text-content-inverse shadow-md hover:bg-content-muted disabled:hover:bg-content`;
  }

-  return `${baseClass} bg-gray-500 dark:text-gray-800 hover:bg-gray-800 dark:hover:bg-gray-100 disabled:hover:bg-gray-500 dark:disabled:hover:bg-transparent`;
+  return `${baseClass} bg-primary-500 text-primary-foreground hover:bg-primary-700 disabled:hover:bg-primary-500`;
 };

 export const Button = forwardRef<HTMLButtonElement, ButtonProps>(
--- a/frontend/src/components/HamburgerMenu.tsx
+++ b/frontend/src/components/HamburgerMenu.tsx
@@ -26,7 +26,6 @@ const adminSubItems: NavItem[] = [
  { path: '/admin/logs', label: 'Logs', icon: SettingsIcon, title: 'Logs' },
 ];

-// Helper function to check if pathname has a prefix
 function hasPrefix(path: string, prefix: string): boolean {
  return path.startsWith(prefix);
 }
@@ -37,10 +36,9 @@ export default function HamburgerMenu() {
  const [isOpen, setIsOpen] = useState(false);
  const isAdmin = user?.is_admin ?? false;

-  // Fetch server info for version
  const { data: infoData } = useGetInfo({
    query: {
-      staleTime: Infinity, // Info doesn't change frequently
+      staleTime: Infinity,
    },
  });
  const version =
@@ -50,7 +48,6 @@ export default function HamburgerMenu() {

  return (
    <div className="relative z-40 ml-6 flex flex-col">
-      {/* Checkbox input for state management */}
      <input
        type="checkbox"
        className="absolute -top-2 z-50 flex size-7 cursor-pointer opacity-0 lg:hidden"
@@ -59,9 +56,8 @@ export default function HamburgerMenu() {
        onChange={e => setIsOpen(e.target.checked)}
      />

-      {/* Hamburger icon lines with CSS animations - hidden on desktop */}
      <span
-        className="z-40 mt-0.5 h-0.5 w-7 bg-black transition-opacity duration-500 lg:hidden dark:bg-white"
+        className="z-40 mt-0.5 h-0.5 w-7 bg-content transition-opacity duration-500 lg:hidden"
        style={{
          transformOrigin: '5px 0px',
          transition:
@@ -70,7 +66,7 @@ export default function HamburgerMenu() {
        }}
      />
      <span
-        className="z-40 mt-1 h-0.5 w-7 bg-black transition-opacity duration-500 lg:hidden dark:bg-white"
+        className="z-40 mt-1 h-0.5 w-7 bg-content transition-opacity duration-500 lg:hidden"
        style={{
          transformOrigin: '0% 100%',
          transition:
@@ -80,7 +76,7 @@ export default function HamburgerMenu() {
        }}
      />
      <span
-        className="z-40 mt-1 h-0.5 w-7 bg-black transition-opacity duration-500 lg:hidden dark:bg-white"
+        className="z-40 mt-1 h-0.5 w-7 bg-content transition-opacity duration-500 lg:hidden"
        style={{
          transformOrigin: '0% 0%',
          transition:
@@ -89,21 +85,17 @@ export default function HamburgerMenu() {
        }}
      />

-      {/* Navigation menu with slide animation */}
      <div
        id="menu"
-        className="fixed -ml-6 h-full w-56 bg-white shadow-lg lg:w-48 dark:bg-gray-700"
+        className="fixed -ml-6 h-full w-56 bg-surface shadow-lg lg:w-48"
        style={{
          top: 0,
          paddingTop: 'env(safe-area-inset-top)',
          transformOrigin: '0% 0%',
-          // On desktop (lg), always show the menu via CSS class
-          // On mobile, control via state
          transform: isOpen ? 'none' : 'translate(-100%, 0)',
          transition: 'transform 0.5s cubic-bezier(0.77, 0.2, 0.05, 1)',
        }}
      >
-        {/* Desktop override - always visible */}
        <style>{`
          @media (min-width: 1024px) {
            #menu {
@@ -112,9 +104,7 @@ export default function HamburgerMenu() {
          }
        `}</style>
        <div className="flex h-16 justify-end lg:justify-around">
-          <p className="my-auto pr-8 text-right text-xl font-bold lg:pr-0 dark:text-white">
-            AnthoLume
-          </p>
+          <p className="my-auto pr-8 text-right text-xl font-bold text-content lg:pr-0">AnthoLume</p>
        </div>
        <nav>
          {navItems.map(item => (
@@ -124,8 +114,8 @@ export default function HamburgerMenu() {
              onClick={() => setIsOpen(false)}
              className={`my-2 flex w-full items-center justify-start border-l-4 p-2 pl-6 transition-colors duration-200 ${
                location.pathname === item.path
-                  ? 'border-purple-500 dark:text-white'
-                  : 'border-transparent text-gray-400 hover:text-gray-800 dark:hover:text-gray-100'
+                  ? 'border-primary-500 text-content'
+                  : 'border-transparent text-content-subtle hover:text-content'
              }`}
            >
              <item.icon size={20} />
@@ -133,23 +123,21 @@ export default function HamburgerMenu() {
            </Link>
          ))}

-          {/* Admin section - only visible for admins */}
          {isAdmin && (
            <div
              className={`my-2 flex flex-col gap-4 border-l-4 p-2 pl-6 transition-colors duration-200 ${
                hasPrefix(location.pathname, '/admin')
-                  ? 'border-purple-500 dark:text-white'
-                  : 'border-transparent text-gray-400'
+                  ? 'border-primary-500 text-content'
+                  : 'border-transparent text-content-subtle'
              }`}
            >
-              {/* Admin header - always shown */}
              <Link
                to="/admin"
                onClick={() => setIsOpen(false)}
                className={`flex w-full justify-start ${
                  location.pathname === '/admin' && !hasPrefix(location.pathname, '/admin/')
-                    ? 'dark:text-white'
-                    : 'text-gray-400 hover:text-gray-800 dark:hover:text-gray-100'
+                    ? 'text-content'
+                    : 'text-content-subtle hover:text-content'
                }`}
              >
                <SettingsIcon size={20} />
@@ -165,8 +153,8 @@ export default function HamburgerMenu() {
                      onClick={() => setIsOpen(false)}
                      className={`flex w-full justify-start ${
                        location.pathname === item.path
-                          ? 'dark:text-white'
-                          : 'text-gray-400 hover:text-gray-800 dark:hover:text-gray-100'
+                          ? 'text-content'
+                          : 'text-content-subtle hover:text-content'
                      }`}
                      style={{ paddingLeft: '1.75em' }}
                    >
@@ -179,7 +167,7 @@ export default function HamburgerMenu() {
          )}
        </nav>
        <a
-          className="absolute bottom-0 flex w-full flex-col items-center justify-center gap-2 p-6 text-black dark:text-white"
+          className="absolute bottom-0 flex w-full flex-col items-center justify-center gap-2 p-6 text-content"
          target="_blank"
          href="https://gitea.va.reichard.io/evan/AnthoLume"
          rel="noreferrer"
--- a/frontend/src/components/Layout.tsx
+++ b/frontend/src/components/Layout.tsx
@@ -3,11 +3,16 @@ import { Link, useLocation, Outlet, Navigate } from 'react-router-dom';
 import { useGetMe } from '../generated/anthoLumeAPIV1';
 import { useAuth } from '../auth/AuthContext';
 import { UserIcon, DropdownIcon } from '../icons';
+import { useTheme } from '../theme/ThemeProvider';
+import type { ThemeMode } from '../utils/localSettings';
 import HamburgerMenu from './HamburgerMenu';

+const themeModes: ThemeMode[] = ['light', 'dark', 'system'];
+
 export default function Layout() {
  const location = useLocation();
  const { isAuthenticated, user, logout, isCheckingAuth } = useAuth();
+  const { themeMode, setThemeMode } = useTheme();
  const { data } = useGetMe(isAuthenticated ? {} : undefined);
  const fetchedUser =
    data?.status === 200 && data.data && 'username' in data.data ? data.data : null;
@@ -20,7 +25,6 @@ export default function Layout() {
    setIsUserDropdownOpen(false);
  };

-  // Close dropdown when clicking outside
  useEffect(() => {
    const handleClickOutside = (event: MouseEvent) => {
      if (dropdownRef.current && !dropdownRef.current.contains(event.target as Node)) {
@@ -34,7 +38,6 @@ export default function Layout() {
    };
  }, []);

-  // Get current page title
  const navItems = [
    { path: '/admin/import-results', title: 'Admin - Import' },
    { path: '/admin/import', title: 'Admin - Import' },
@@ -57,43 +60,62 @@ export default function Layout() {
    document.title = `AnthoLume - ${currentPageTitle}`;
  }, [currentPageTitle]);

-  // Show loading while checking authentication status
  if (isCheckingAuth) {
-    return <div className="text-gray-500 dark:text-white">Loading...</div>;
+    return <div className="text-content-muted">Loading...</div>;
  }

-  // Redirect to login if not authenticated
  if (!isAuthenticated) {
    return <Navigate to="/login" replace />;
  }

  return (
-    <div className="min-h-screen bg-gray-100 dark:bg-gray-800">
-      {/* Header */}
+    <div className="min-h-screen bg-canvas">
      <div className="flex h-16 w-full items-center justify-between">
-        {/* Mobile Navigation Button with CSS animations */}
        <HamburgerMenu />

-        {/* Header Title */}
-        <h1 className="whitespace-nowrap px-6 text-xl font-bold lg:ml-44 dark:text-white">
+        <h1 className="whitespace-nowrap px-6 text-xl font-bold text-content lg:ml-44">
          {currentPageTitle}
        </h1>

-        {/* User Dropdown */}
        <div
          className="relative flex w-full items-center justify-end space-x-4 p-4"
          ref={dropdownRef}
        >
          <button
            onClick={() => setIsUserDropdownOpen(!isUserDropdownOpen)}
-            className="relative block text-gray-800 dark:text-gray-200"
+            className="relative block text-content"
          >
            <UserIcon size={20} />
          </button>

          {isUserDropdownOpen && (
            <div className="absolute right-4 top-16 z-20 pt-4 transition duration-200">
-              <div className="w-40 origin-top-right rounded-md bg-white shadow-lg ring-1 ring-black/5 dark:bg-gray-700 dark:shadow-gray-800">
+              <div className="w-64 origin-top-right rounded-md bg-surface shadow-lg ring-1 ring-black/5 dark:shadow-gray-800">
+                <div
+                  className="border-b border-border px-4 py-3"
+                  role="group"
+                  aria-label="Theme mode"
+                >
+                  <p className="mb-2 text-xs font-semibold uppercase tracking-wide text-content-subtle">
+                    Theme
+                  </p>
+                  <div className="inline-flex w-full rounded border border-border bg-surface-muted p-1">
+                    {themeModes.map(mode => (
+                      <button
+                        key={mode}
+                        type="button"
+                        onClick={() => setThemeMode(mode)}
+                        className={`flex-1 rounded px-2 py-1 text-xs font-medium capitalize transition-colors ${
+                          themeMode === mode
+                            ? 'bg-content text-content-inverse'
+                            : 'text-content-muted hover:bg-surface hover:text-content'
+                        }`}
+                      >
+                        {mode}
+                      </button>
+                    ))}
+                  </div>
+                </div>
                <div
                  className="py-1"
                  role="menu"
@@ -103,7 +125,7 @@ export default function Layout() {
                  <Link
                    to="/settings"
                    onClick={() => setIsUserDropdownOpen(false)}
-                    className="block px-4 py-2 text-gray-700 hover:bg-gray-100 hover:text-gray-900 dark:text-gray-100 dark:hover:bg-gray-600 dark:hover:text-white"
+                    className="block px-4 py-2 text-content-muted hover:bg-surface-muted hover:text-content"
                    role="menuitem"
                  >
                    <span className="flex flex-col">
@@ -112,7 +134,7 @@ export default function Layout() {
                  </Link>
                  <button
                    onClick={handleLogout}
-                    className="block w-full px-4 py-2 text-left text-gray-700 hover:bg-gray-100 hover:text-gray-900 dark:text-gray-100 dark:hover:bg-gray-600 dark:hover:text-white"
+                    className="block w-full px-4 py-2 text-left text-content-muted hover:bg-surface-muted hover:text-content"
                    role="menuitem"
                  >
                    <span className="flex flex-col">
@@ -126,11 +148,11 @@ export default function Layout() {

          <button
            onClick={() => setIsUserDropdownOpen(!isUserDropdownOpen)}
-            className="flex cursor-pointer items-center gap-2 py-4 text-gray-500 dark:text-white"
+            className="flex cursor-pointer items-center gap-2 py-4 text-content-muted"
          >
            <span>{userData ? ('username' in userData ? userData.username : 'User') : 'User'}</span>
            <span
-              className="text-gray-800 transition-transform duration-200 dark:text-gray-200"
+              className="text-content transition-transform duration-200"
              style={{ transform: isUserDropdownOpen ? 'rotate(180deg)' : 'rotate(0deg)' }}
            >
              <DropdownIcon size={20} />
@@ -139,7 +161,6 @@ export default function Layout() {
        </div>
      </div>

-      {/* Main Content */}
      <main
        className="relative overflow-hidden"
        style={{ height: 'calc(100dvh - 4rem - env(safe-area-inset-top))' }}
--- a/frontend/src/components/LoadingState.tsx
+++ b/frontend/src/components/LoadingState.tsx
@@ -13,13 +13,8 @@ export function LoadingState({
  iconSize = 24,
 }: LoadingStateProps) {
  return (
-    <div
-      className={cn(
-        'flex items-center justify-center gap-3 text-gray-500 dark:text-gray-400',
-        className,
-      )}
-    >
-      <LoadingIcon size={iconSize} className="text-purple-600 dark:text-purple-400" />
+    <div className={cn('flex items-center justify-center gap-3 text-content-muted', className)}>
+      <LoadingIcon size={iconSize} className="text-primary-500" />
      <span className="text-sm font-medium">{message}</span>
    </div>
  );
--- a/frontend/src/components/Skeleton.tsx
+++ b/frontend/src/components/Skeleton.tsx
@@ -19,7 +19,7 @@ export function Skeleton({

  const variantClasses = {
    default: 'rounded',
-    text: 'rounded-md h-4',
+    text: 'h-4 rounded-md',
    circular: 'rounded-full',
    rectangular: 'rounded-none',
  };
@@ -97,12 +97,7 @@ export function SkeletonCard({
  textLines = 3,
 }: SkeletonCardProps) {
  return (
-    <div
-      className={cn(
-        'bg-white dark:bg-gray-700 rounded-lg p-4 border dark:border-gray-600',
-        className
-      )}
-    >
+    <div className={cn('rounded-lg border border-border bg-surface p-4', className)}>
      {showAvatar && (
        <div className="mb-4 flex items-start gap-4">
          <SkeletonAvatar />
@@ -132,11 +127,11 @@ export function SkeletonTable({
  showHeader = true,
 }: SkeletonTableProps) {
  return (
-    <div className={cn('bg-white dark:bg-gray-700 rounded-lg overflow-hidden', className)}>
+    <div className={cn('overflow-hidden rounded-lg bg-surface', className)}>
      <table className="min-w-full">
        {showHeader && (
          <thead>
-            <tr className="border-b dark:border-gray-600">
+            <tr className="border-b border-border">
              {Array.from({ length: columns }).map((_, i) => (
                <th key={i} className="p-3">
                  <Skeleton variant="text" className="h-5 w-3/4" />
@@ -147,7 +142,7 @@ export function SkeletonTable({
        )}
        <tbody>
          {Array.from({ length: rows }).map((_, rowIndex) => (
-            <tr key={rowIndex} className="border-b last:border-0 dark:border-gray-600">
+            <tr key={rowIndex} className="border-b border-border last:border-0">
              {Array.from({ length: columns }).map((_, colIndex) => (
                <td key={colIndex} className="p-3">
                  <Skeleton
@@ -187,11 +182,11 @@ interface PageLoaderProps {

 export function PageLoader({ message = 'Loading...', className = '' }: PageLoaderProps) {
  return (
-    <div className={cn('flex flex-col items-center justify-center min-h-[400px] gap-4', className)}>
+    <div className={cn('flex min-h-[400px] flex-col items-center justify-center gap-4', className)}>
      <div className="relative">
-        <div className="size-12 animate-spin rounded-full border-4 border-gray-200 border-t-blue-500 dark:border-gray-600" />
+        <div className="size-12 animate-spin rounded-full border-4 border-gray-200 border-t-secondary-500 dark:border-gray-600" />
      </div>
-      <p className="text-sm font-medium text-gray-500 dark:text-gray-400">{message}</p>
+      <p className="text-sm font-medium text-content-muted">{message}</p>
    </div>
  );
 }
@@ -203,19 +198,18 @@ interface InlineLoaderProps {

 export function InlineLoader({ size = 'md', className = '' }: InlineLoaderProps) {
  const sizeMap = {
-    sm: 'w-4 h-4 border-2',
-    md: 'w-6 h-6 border-3',
-    lg: 'w-8 h-8 border-4',
+    sm: 'h-4 w-4 border-2',
+    md: 'h-6 w-6 border-[3px]',
+    lg: 'h-8 w-8 border-4',
  };

  return (
    <div className={cn('flex items-center justify-center', className)}>
      <div
-        className={`${sizeMap[size]} animate-spin rounded-full border-gray-200 border-t-blue-500 dark:border-gray-600`}
+        className={`${sizeMap[size]} animate-spin rounded-full border-gray-200 border-t-secondary-500 dark:border-gray-600`}
      />
    </div>
  );
 }

-// Re-export SkeletonTable for backward compatibility
 export { SkeletonTable as SkeletonTableExport };
--- a/frontend/src/components/Table.tsx
+++ b/frontend/src/components/Table.tsx
@@ -27,10 +27,10 @@ function SkeletonTable({
  className?: string;
 }) {
  return (
-    <div className={cn('overflow-hidden rounded-lg bg-white dark:bg-gray-700', className)}>
+    <div className={cn('overflow-hidden rounded-lg bg-surface', className)}>
      <table className="min-w-full">
        <thead>
-          <tr className="border-b dark:border-gray-600">
+          <tr className="border-b border-border">
            {Array.from({ length: columns }).map((_, i) => (
              <th key={i} className="p-3">
                <Skeleton variant="text" className="h-5 w-3/4" />
@@ -40,7 +40,7 @@ function SkeletonTable({
        </thead>
        <tbody>
          {Array.from({ length: rows }).map((_, rowIndex) => (
-            <tr key={rowIndex} className="border-b last:border-0 dark:border-gray-600">
+            <tr key={rowIndex} className="border-b border-border last:border-0">
              {Array.from({ length: columns }).map((_, colIndex) => (
                <td key={colIndex} className="p-3">
                  <Skeleton
@@ -81,13 +81,13 @@ export function Table<T extends object>({
  return (
    <div className="overflow-x-auto">
      <div className="inline-block min-w-full overflow-hidden rounded shadow">
-        <table className="min-w-full bg-white dark:bg-gray-700">
+        <table className="min-w-full bg-surface">
          <thead>
-            <tr className="border-b dark:border-gray-600">
+            <tr className="border-b border-border">
              {columns.map(column => (
                <th
                  key={String(column.key)}
-                  className={`p-3 text-left text-gray-500 dark:text-white ${column.className || ''}`}
+                  className={`p-3 text-left text-content-muted ${column.className || ''}`}
                >
                  {column.header}
                </th>
@@ -97,20 +97,17 @@ export function Table<T extends object>({
          <tbody>
            {data.length === 0 ? (
              <tr>
-                <td
-                  colSpan={columns.length}
-                  className="p-3 text-center text-gray-700 dark:text-gray-300"
-                >
+                <td colSpan={columns.length} className="p-3 text-center text-content-muted">
                  {emptyMessage}
                </td>
              </tr>
            ) : (
              data.map((row, index) => (
-                <tr key={getRowKey(row, index)} className="border-b dark:border-gray-600">
+                <tr key={getRowKey(row, index)} className="border-b border-border">
                  {columns.map(column => (
                    <td
                      key={`${getRowKey(row, index)}-${String(column.key)}`}
-                      className={`p-3 text-gray-700 dark:text-gray-300 ${column.className || ''}`}
+                      className={`p-3 text-content ${column.className || ''}`}
                    >
                      {column.render
                        ? column.render(row[column.key], row, index)
--- a/frontend/src/components/Toast.tsx
+++ b/frontend/src/components/Toast.tsx
@@ -13,24 +13,24 @@ export interface ToastProps {

 const getToastStyles = (_type: ToastType) => {
  const baseStyles =
-    'flex items-center gap-3 p-4 rounded-lg shadow-lg border-l-4 transition-all duration-300';
+    'flex items-center gap-3 rounded-lg border-l-4 p-4 shadow-lg transition-all duration-300';

  const typeStyles = {
-    info: 'bg-blue-50 dark:bg-blue-900/30 border-blue-500 dark:border-blue-400',
-    warning: 'bg-yellow-50 dark:bg-yellow-900/30 border-yellow-500 dark:border-yellow-400',
-    error: 'bg-red-50 dark:bg-red-900/30 border-red-500 dark:border-red-400',
+    info: 'border-secondary-500 bg-secondary-50 dark:bg-secondary-100/20',
+    warning: 'border-yellow-500 bg-yellow-50 dark:bg-yellow-100/20',
+    error: 'border-red-500 bg-red-50 dark:bg-red-100/20',
  };

  const iconStyles = {
-    info: 'text-blue-600 dark:text-blue-400',
-    warning: 'text-yellow-600 dark:text-yellow-400',
+    info: 'text-secondary-600 dark:text-secondary-500',
+    warning: 'text-yellow-700 dark:text-yellow-500',
    error: 'text-red-600 dark:text-red-400',
  };

  const textStyles = {
-    info: 'text-blue-800 dark:text-blue-200',
-    warning: 'text-yellow-800 dark:text-yellow-200',
-    error: 'text-red-800 dark:text-red-200',
+    info: 'text-secondary-900 dark:text-secondary-700',
+    warning: 'text-yellow-900 dark:text-yellow-700',
+    error: 'text-red-900 dark:text-red-700',
  };

  return { baseStyles, typeStyles, iconStyles, textStyles };
--- a/frontend/src/icons/BaseIcon.tsx
+++ b/frontend/src/icons/BaseIcon.tsx
@@ -18,9 +18,9 @@ export function BaseIcon({
  children,
 }: BaseIconProps) {
  const disabledClasses = disabled
-    ? 'text-gray-200 dark:text-gray-600'
+    ? 'text-content-subtle'
    : hoverable
-      ? 'hover:text-gray-800 dark:hover:text-gray-100'
+      ? 'hover:text-content'
      : '';

  return (
--- a/frontend/src/icons/GitIcon.tsx
+++ b/frontend/src/icons/GitIcon.tsx
@@ -7,7 +7,7 @@ export function GitIcon({ size = 20, className = '' }: GitIconProps) {
  return (
    <svg
      xmlns="http://www.w3.org/2000/svg"
-      className={`${className} text-black dark:text-white`.trim()}
+      className={`${className} text-content`.trim()}
      height={size}
      viewBox="0 0 219 92"
      fill="currentColor"
--- a/frontend/src/index.css
+++ b/frontend/src/index.css
@@ -2,16 +2,208 @@
@tailwind components;
@tailwind utilities;

-/* PWA Styling */
+:root {
+  --white: 255 255 255;
+  --black: 0 0 0;
+
+  --canvas: 243 244 246;
+  --surface: 255 255 255;
+  --surface-muted: 249 250 251;
+  --surface-strong: 209 213 219;
+  --overlay: 31 41 55;
+
+  --content: 0 0 0;
+  --content-muted: 107 114 128;
+  --content-subtle: 156 163 175;
+  --content-inverse: 255 255 255;
+
+  --border: 209 213 219;
+  --border-muted: 229 231 235;
+  --border-strong: 156 163 175;
+
+  --neutral-50: 249 250 251;
+  --neutral-100: 243 244 246;
+  --neutral-200: 229 231 235;
+  --neutral-300: 209 213 219;
+  --neutral-400: 156 163 175;
+  --neutral-500: 107 114 128;
+  --neutral-600: 75 85 99;
+  --neutral-700: 55 65 81;
+  --neutral-800: 31 41 55;
+  --neutral-900: 17 24 39;
+
+  --primary-50: 250 245 255;
+  --primary-100: 243 232 255;
+  --primary-200: 233 213 255;
+  --primary-300: 216 180 254;
+  --primary-400: 192 132 252;
+  --primary-500: 168 85 247;
+  --primary-600: 147 51 234;
+  --primary-700: 126 34 206;
+  --primary-800: 107 33 168;
+  --primary-900: 88 28 135;
+  --primary-foreground: 255 255 255;
+
+  --secondary-50: 239 246 255;
+  --secondary-100: 219 234 254;
+  --secondary-200: 191 219 254;
+  --secondary-300: 147 197 253;
+  --secondary-400: 96 165 250;
+  --secondary-500: 59 130 246;
+  --secondary-600: 37 99 235;
+  --secondary-700: 29 78 216;
+  --secondary-800: 30 64 175;
+  --secondary-900: 30 58 138;
+  --secondary-foreground: 255 255 255;
+
+  --tertiary-50: 236 253 245;
+  --tertiary-100: 209 250 229;
+  --tertiary-200: 167 243 208;
+  --tertiary-300: 110 231 183;
+  --tertiary-400: 52 211 153;
+  --tertiary-500: 16 185 129;
+  --tertiary-600: 5 150 105;
+  --tertiary-700: 4 120 87;
+  --tertiary-800: 6 95 70;
+  --tertiary-900: 6 78 59;
+  --tertiary-foreground: 255 255 255;
+
+  --warning-50: 254 252 232;
+  --warning-100: 254 249 195;
+  --warning-200: 254 240 138;
+  --warning-300: 253 224 71;
+  --warning-400: 250 204 21;
+  --warning-500: 234 179 8;
+  --warning-600: 202 138 4;
+  --warning-700: 161 98 7;
+  --warning-800: 133 77 14;
+  --warning-900: 113 63 18;
+  --warning-foreground: 17 24 39;
+
+  --error-50: 254 242 242;
+  --error-100: 254 226 226;
+  --error-200: 254 202 202;
+  --error-300: 252 165 165;
+  --error-400: 248 113 113;
+  --error-500: 239 68 68;
+  --error-600: 220 38 38;
+  --error-700: 185 28 28;
+  --error-800: 153 27 27;
+  --error-900: 127 29 29;
+  --error-foreground: 255 255 255;
+}
+
+.dark {
+  --white: 255 255 255;
+  --black: 0 0 0;
+
+  --canvas: 31 41 55;
+  --surface: 55 65 81;
+  --surface-muted: 75 85 99;
+  --surface-strong: 107 114 128;
+  --overlay: 229 231 235;
+
+  --content: 255 255 255;
+  --content-muted: 209 213 219;
+  --content-subtle: 156 163 175;
+  --content-inverse: 17 24 39;
+
+  --border: 75 85 99;
+  --border-muted: 55 65 81;
+  --border-strong: 107 114 128;
+
+  --neutral-50: 249 250 251;
+  --neutral-100: 243 244 246;
+  --neutral-200: 229 231 235;
+  --neutral-300: 209 213 219;
+  --neutral-400: 156 163 175;
+  --neutral-500: 107 114 128;
+  --neutral-600: 75 85 99;
+  --neutral-700: 55 65 81;
+  --neutral-800: 31 41 55;
+  --neutral-900: 17 24 39;
+
+  --primary-50: 250 245 255;
+  --primary-100: 243 232 255;
+  --primary-200: 233 213 255;
+  --primary-300: 216 180 254;
+  --primary-400: 192 132 252;
+  --primary-500: 168 85 247;
+  --primary-600: 147 51 234;
+  --primary-700: 126 34 206;
+  --primary-800: 107 33 168;
+  --primary-900: 88 28 135;
+  --primary-foreground: 255 255 255;
+
+  --secondary-50: 239 246 255;
+  --secondary-100: 219 234 254;
+  --secondary-200: 191 219 254;
+  --secondary-300: 147 197 253;
+  --secondary-400: 96 165 250;
+  --secondary-500: 59 130 246;
+  --secondary-600: 37 99 235;
+  --secondary-700: 29 78 216;
+  --secondary-800: 30 64 175;
+  --secondary-900: 30 58 138;
+  --secondary-foreground: 255 255 255;
+
+  --tertiary-50: 236 253 245;
+  --tertiary-100: 209 250 229;
+  --tertiary-200: 167 243 208;
+  --tertiary-300: 110 231 183;
+  --tertiary-400: 52 211 153;
+  --tertiary-500: 16 185 129;
+  --tertiary-600: 5 150 105;
+  --tertiary-700: 4 120 87;
+  --tertiary-800: 6 95 70;
+  --tertiary-900: 6 78 59;
+  --tertiary-foreground: 255 255 255;
+
+  --warning-50: 254 252 232;
+  --warning-100: 254 249 195;
+  --warning-200: 254 240 138;
+  --warning-300: 253 224 71;
+  --warning-400: 250 204 21;
+  --warning-500: 234 179 8;
+  --warning-600: 202 138 4;
+  --warning-700: 161 98 7;
+  --warning-800: 133 77 14;
+  --warning-900: 113 63 18;
+  --warning-foreground: 17 24 39;
+
+  --error-50: 254 242 242;
+  --error-100: 254 226 226;
+  --error-200: 254 202 202;
+  --error-300: 252 165 165;
+  --error-400: 248 113 113;
+  --error-500: 239 68 68;
+  --error-600: 220 38 38;
+  --error-700: 185 28 28;
+  --error-800: 153 27 27;
+  --error-900: 127 29 29;
+  --error-foreground: 255 255 255;
+}
+
+@layer base {
  html,
  body {
    overscroll-behavior-y: none;
-  margin: 0px;
+    margin: 0;
  }

  html {
    height: calc(100% + env(safe-area-inset-bottom));
    padding: env(safe-area-inset-top) env(safe-area-inset-right) 0 env(safe-area-inset-left);
+    background-color: rgb(var(--canvas));
+  }
+
+  body {
+    background-color: rgb(var(--canvas));
+    color: rgb(var(--content));
+    transition:
+      background-color 150ms ease,
+      color 150ms ease;
+  }
 }

 main {
@@ -46,7 +238,7 @@ main {

 /* Mobile Navigation */
 #mobile-nav-button span {
-  transform-origin: 5px 0px;
+  transform-origin: 5px 0;
  transition:
    transform 0.5s cubic-bezier(0.77, 0.2, 0.05, 1),
    background 0.5s cubic-bezier(0.77, 0.2, 0.05, 1),
@@ -54,11 +246,11 @@ main {
 }

 #mobile-nav-button span:first-child {
-  transform-origin: 0% 0%;
+  transform-origin: 0 0;
 }

 #mobile-nav-button span:nth-last-child(2) {
-  transform-origin: 0% 100%;
+  transform-origin: 0 100%;
 }

 #mobile-nav-button:checked ~ span {
@@ -88,7 +280,7 @@ main {
 #menu {
  top: 0;
  padding-top: env(safe-area-inset-top);
-  transform-origin: 0% 0%;
+  transform-origin: 0 0;
  transform: translate(-100%, 0);
  transition: transform 0.5s cubic-bezier(0.77, 0.2, 0.05, 1);
 }
@@ -112,9 +304,9 @@ main {
 .animate-wave {
  background: linear-gradient(
    90deg,
-    rgb(229, 231, 235) 0%,
-    rgb(243, 244, 246) 50%,
-    rgb(229, 231, 235) 100%
+    rgb(var(--neutral-200)) 0%,
+    rgb(var(--neutral-100)) 50%,
+    rgb(var(--neutral-200)) 100%
  );
  background-size: 200% 100%;
  animation: wave 1.5s ease-in-out infinite;
@@ -123,9 +315,9 @@ main {
 .dark .animate-wave {
  background: linear-gradient(
    90deg,
-    rgb(75, 85, 99) 0%,
-    rgb(107, 114, 128) 50%,
-    rgb(75, 85, 99) 100%
+    rgb(var(--neutral-600)) 0%,
+    rgb(var(--neutral-500)) 50%,
+    rgb(var(--neutral-600)) 100%
  );
  background-size: 200% 100%;
 }
--- a/frontend/src/main.tsx
+++ b/frontend/src/main.tsx
@@ -5,10 +5,12 @@ import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
 import axios from 'axios';
 import { ToastProvider } from './components/ToastContext';
 import { setupAuthInterceptors } from './auth/authInterceptor';
+import { ThemeProvider, initializeThemeMode } from './theme/ThemeProvider';
 import App from './App';
 import './index.css';

 setupAuthInterceptors(axios);
+initializeThemeMode();

 const queryClient = new QueryClient({
  defaultOptions: {
@@ -26,9 +28,11 @@ ReactDOM.createRoot(document.getElementById('root')!).render(
  <React.StrictMode>
    <QueryClientProvider client={queryClient}>
      <BrowserRouter>
+        <ThemeProvider>
          <ToastProvider>
            <App />
          </ToastProvider>
+        </ThemeProvider>
      </BrowserRouter>
    </QueryClientProvider>
  </React.StrictMode>
--- a/frontend/src/pages/DocumentsPage.tsx
+++ b/frontend/src/pages/DocumentsPage.tsx
@@ -8,19 +8,11 @@ import { useToasts } from '../components/ToastContext';
 import { formatDuration } from '../utils/formatters';
 import { useDebounce } from '../hooks/useDebounce';
 import { getErrorMessage } from '../utils/errors';
-
-const DOCUMENTS_VIEW_MODE_KEY = 'documents:view-mode';
-
-type DocumentViewMode = 'grid' | 'list';
-
-function getInitialViewMode(): DocumentViewMode {
-  if (typeof window === 'undefined') {
-    return 'grid';
-  }
-
-  const storedValue = window.localStorage.getItem(DOCUMENTS_VIEW_MODE_KEY);
-  return storedValue === 'list' ? 'list' : 'grid';
-}
+import {
+  getDocumentsViewMode,
+  setDocumentsViewMode,
+  type DocumentsViewMode,
+} from '../utils/localSettings';

 interface DocumentCardProps {
  doc: Document;
@@ -36,7 +28,7 @@ function DocumentCard({ doc }: DocumentCardProps) {
      <div
        role="link"
        tabIndex={0}
-        className="flex size-full cursor-pointer gap-4 rounded bg-white p-4 shadow-lg transition-colors hover:bg-gray-50 focus:outline-none dark:bg-gray-700 dark:hover:bg-gray-600"
+        className="flex size-full cursor-pointer gap-4 rounded bg-surface p-4 shadow-lg transition-colors hover:bg-surface-muted focus:outline-none"
        onClick={() => navigate(`/documents/${doc.id}`)}
        onKeyDown={event => {
          if (event.key === 'Enter' || event.key === ' ') {
@@ -52,33 +44,33 @@ function DocumentCard({ doc }: DocumentCardProps) {
            alt={doc.title}
          />
        </div>
-        <div className="flex w-full flex-col justify-around text-sm dark:text-white">
+        <div className="flex w-full flex-col justify-around text-sm text-content">
          <div className="inline-flex shrink-0 items-center">
            <div>
-              <p className="text-gray-400">Title</p>
+              <p className="text-content-subtle">Title</p>
              <p className="font-medium">{doc.title || 'Unknown'}</p>
            </div>
          </div>
          <div className="inline-flex shrink-0 items-center">
            <div>
-              <p className="text-gray-400">Author</p>
+              <p className="text-content-subtle">Author</p>
              <p className="font-medium">{doc.author || 'Unknown'}</p>
            </div>
          </div>
          <div className="inline-flex shrink-0 items-center">
            <div>
-              <p className="text-gray-400">Progress</p>
+              <p className="text-content-subtle">Progress</p>
              <p className="font-medium">{percentage}%</p>
            </div>
          </div>
          <div className="inline-flex shrink-0 items-center">
            <div>
-              <p className="text-gray-400">Time Read</p>
+              <p className="text-content-subtle">Time Read</p>
              <p className="font-medium">{formatDuration(totalTimeSeconds)}</p>
            </div>
          </div>
        </div>
-        <div className="absolute bottom-4 right-4 flex flex-col gap-2 text-gray-500 dark:text-gray-400">
+        <div className="absolute bottom-4 right-4 flex flex-col gap-2 text-content-muted">
          <Link to={`/activity?document=${doc.id}`} onClick={e => e.stopPropagation()}>
            <ActivityIcon size={20} />
          </Link>
@@ -108,7 +100,7 @@ function DocumentListItem({ doc }: DocumentListItemProps) {
    <div
      role="link"
      tabIndex={0}
-      className="block cursor-pointer rounded bg-white p-4 shadow-lg transition-colors hover:bg-gray-50 focus:outline-none dark:bg-gray-700 dark:text-white dark:hover:bg-gray-600"
+      className="block cursor-pointer rounded bg-surface p-4 text-content shadow-lg transition-colors hover:bg-surface-muted focus:outline-none"
      onClick={() => navigate(`/documents/${doc.id}`)}
      onKeyDown={event => {
        if (event.key === 'Enter' || event.key === ' ') {
@@ -120,24 +112,24 @@ function DocumentListItem({ doc }: DocumentListItemProps) {
      <div className="flex flex-col gap-4 sm:flex-row sm:items-center">
        <div className="grid flex-1 grid-cols-1 gap-3 text-sm md:grid-cols-4">
          <div>
-            <p className="text-gray-400">Title</p>
+            <p className="text-content-subtle">Title</p>
            <p className="font-medium">{doc.title || 'Unknown'}</p>
          </div>
          <div>
-            <p className="text-gray-400">Author</p>
+            <p className="text-content-subtle">Author</p>
            <p className="font-medium">{doc.author || 'Unknown'}</p>
          </div>
          <div>
-            <p className="text-gray-400">Progress</p>
+            <p className="text-content-subtle">Progress</p>
            <p className="font-medium">{percentage}%</p>
          </div>
          <div>
-            <p className="text-gray-400">Time Read</p>
+            <p className="text-content-subtle">Time Read</p>
            <p className="font-medium">{formatDuration(totalTimeSeconds)}</p>
          </div>
        </div>

-        <div className="flex shrink-0 items-center justify-end gap-4 text-gray-500 dark:text-gray-400">
+        <div className="flex shrink-0 items-center justify-end gap-4 text-content-muted">
          <Link to={`/activity?document=${doc.id}`} onClick={e => e.stopPropagation()}>
            <ActivityIcon size={20} />
          </Link>
@@ -159,17 +151,16 @@ export default function DocumentsPage() {
  const [page, setPage] = useState(1);
  const [limit] = useState(9);
  const [uploadMode, setUploadMode] = useState(false);
-  const [viewMode, setViewMode] = useState<DocumentViewMode>(getInitialViewMode);
+  const [viewMode, setViewMode] = useState<DocumentsViewMode>(getDocumentsViewMode);
  const fileInputRef = useRef<HTMLInputElement>(null);
  const { showInfo, showWarning, showError } = useToasts();

  const debouncedSearch = useDebounce(search, 300);

  useEffect(() => {
-    window.localStorage.setItem(DOCUMENTS_VIEW_MODE_KEY, viewMode);
+    setDocumentsViewMode(viewMode);
  }, [viewMode]);

-  // Reset to page 1 when search changes
  useEffect(() => {
    setPage(1);
  }, [debouncedSearch]);
@@ -210,45 +201,44 @@ export default function DocumentsPage() {
    }
  };

+  const getViewModeButtonClasses = (mode: DocumentsViewMode) =>
+    `rounded px-3 py-1 text-sm font-medium transition-colors ${
+      viewMode === mode
+        ? 'bg-content text-content-inverse'
+        : 'text-content-muted hover:bg-surface-muted'
+    }`;
+
  return (
    <div className="flex flex-col gap-4">
-      <div className="flex grow flex-col gap-4 rounded bg-white p-4 text-gray-500 shadow-lg dark:bg-gray-700 dark:text-white">
+      <div className="flex grow flex-col gap-4 rounded bg-surface p-4 text-content-muted shadow-lg">
        <div className="flex flex-col gap-4 lg:flex-row">
          <div className="flex w-full grow flex-col">
            <div className="relative flex">
-              <span className="inline-flex items-center border-y border-l border-gray-300 bg-white px-3 text-sm text-gray-500 shadow-sm">
+              <span className="inline-flex items-center border-y border-l border-border bg-surface px-3 text-sm text-content-muted shadow-sm">
                <Search2Icon size={15} hoverable={false} />
              </span>
              <input
                type="text"
                value={search}
                onChange={e => setSearch(e.target.value)}
-                className="w-full flex-1 appearance-none rounded-none border border-gray-300 bg-white p-2 text-base text-gray-700 shadow-sm placeholder:text-gray-400 focus:border-transparent focus:outline-none focus:ring-2 focus:ring-purple-600"
+                className="w-full flex-1 appearance-none rounded-none border border-border bg-surface px-4 py-2 text-base text-content shadow-sm placeholder:text-content-subtle focus:border-transparent focus:outline-none focus:ring-2 focus:ring-primary-600"
                placeholder="Search Author / Title"
                name="search"
              />
            </div>
          </div>
-          <div className="inline-flex rounded border border-gray-300 bg-white p-1 dark:border-gray-600 dark:bg-gray-800">
+          <div className="inline-flex rounded border border-border bg-surface p-1">
            <button
              type="button"
              onClick={() => setViewMode('grid')}
-              className={`rounded px-3 py-1 text-sm font-medium transition-colors ${
-                viewMode === 'grid'
-                  ? 'bg-gray-800 text-white dark:bg-gray-100 dark:text-gray-900'
-                  : 'text-gray-600 hover:bg-gray-100 dark:text-gray-300 dark:hover:bg-gray-700'
-              }`}
+              className={getViewModeButtonClasses('grid')}
            >
              Grid
            </button>
            <button
              type="button"
              onClick={() => setViewMode('list')}
-              className={`rounded px-3 py-1 text-sm font-medium transition-colors ${
-                viewMode === 'list'
-                  ? 'bg-gray-800 text-white dark:bg-gray-100 dark:text-gray-900'
-                  : 'text-gray-600 hover:bg-gray-100 dark:text-gray-300 dark:hover:bg-gray-700'
-              }`}
+              className={getViewModeButtonClasses('list')}
            >
              List
            </button>
@@ -263,7 +253,7 @@ export default function DocumentsPage() {
          ) : docs && docs.length > 0 ? (
            docs.map(doc => <DocumentCard key={doc.id} doc={doc} />)
          ) : (
-            <div className="col-span-full rounded bg-white p-6 text-center text-gray-500 shadow-lg dark:bg-gray-700 dark:text-gray-300">
+            <div className="col-span-full rounded bg-surface p-6 text-center text-content-muted shadow-lg">
              No documents found.
            </div>
          )}
@@ -275,18 +265,18 @@ export default function DocumentsPage() {
          ) : docs && docs.length > 0 ? (
            docs.map(doc => <DocumentListItem key={doc.id} doc={doc} />)
          ) : (
-            <div className="rounded bg-white p-6 text-center text-gray-500 shadow-lg dark:bg-gray-700 dark:text-gray-300">
+            <div className="rounded bg-surface p-6 text-center text-content-muted shadow-lg">
              No documents found.
            </div>
          )}
        </div>
      )}

-      <div className="mt-4 flex w-full justify-center gap-4 text-black dark:text-white">
+      <div className="mt-4 flex w-full justify-center gap-4 text-content">
        {previousPage && previousPage > 0 && (
          <button
            onClick={() => setPage(page - 1)}
-            className="w-24 rounded bg-white p-2 text-center text-sm font-medium shadow-lg hover:bg-gray-400 focus:outline-none dark:bg-gray-600 dark:hover:bg-gray-700"
+            className="w-24 rounded bg-surface p-2 text-center text-sm font-medium shadow-lg hover:bg-surface-strong focus:outline-none"
          >
            ◄
          </button>
@@ -294,7 +284,7 @@ export default function DocumentsPage() {
        {nextPage && nextPage > 0 && (
          <button
            onClick={() => setPage(page + 1)}
-            className="w-24 rounded bg-white p-2 text-center text-sm font-medium shadow-lg hover:bg-gray-400 focus:outline-none dark:bg-gray-600 dark:hover:bg-gray-700"
+            className="w-24 rounded bg-surface p-2 text-center text-sm font-medium shadow-lg hover:bg-surface-strong focus:outline-none"
          >
            ►
          </button>
@@ -310,7 +300,7 @@ export default function DocumentsPage() {
          onChange={() => setUploadMode(!uploadMode)}
        />
        <div
-          className={`absolute bottom-0 right-0 z-10 flex w-72 flex-col gap-2 rounded bg-gray-800 p-4 text-sm text-white transition-opacity duration-200 dark:bg-gray-200 dark:text-black ${uploadMode ? 'visible opacity-100' : 'invisible opacity-0'}`}
+          className={`absolute bottom-0 right-0 z-10 flex w-72 flex-col gap-2 rounded bg-content p-4 text-sm text-content-inverse transition-opacity duration-200 ${uploadMode ? 'visible opacity-100' : 'invisible opacity-0'}`}
        >
          <form method="POST" encType="multipart/form-data" className="flex flex-col gap-2">
            <input
@@ -322,7 +312,7 @@ export default function DocumentsPage() {
              onChange={handleFileChange}
            />
            <button
-              className="bg-gray-500 px-2 py-1 font-medium text-gray-800 hover:bg-gray-100 dark:text-white dark:hover:bg-gray-800"
+              className="bg-surface-strong px-2 py-1 font-medium text-content hover:bg-surface"
              type="submit"
              onClick={e => {
                e.preventDefault();
@@ -336,7 +326,7 @@ export default function DocumentsPage() {
          </form>
          <label htmlFor="upload-file-button">
            <div
-              className="mt-2 w-full cursor-pointer bg-gray-500 px-2 py-1 text-center font-medium text-gray-800 hover:bg-gray-100 dark:text-white dark:hover:bg-gray-800"
+              className="mt-2 w-full cursor-pointer bg-surface-strong px-2 py-1 text-center font-medium text-content hover:bg-surface"
              onClick={handleCancelUpload}
            >
              Cancel Upload
@@ -344,10 +334,10 @@ export default function DocumentsPage() {
          </label>
        </div>
        <label
-          className="flex size-16 cursor-pointer items-center justify-center rounded-full bg-gray-800 opacity-30 transition-all duration-200 hover:opacity-100 dark:bg-gray-200"
+          className="flex size-16 cursor-pointer items-center justify-center rounded-full bg-content opacity-30 transition-all duration-200 hover:opacity-100"
          htmlFor="upload-file-button"
        >
-          <UploadIcon size={34} />
+          <UploadIcon size={34} className="text-content-inverse" />
        </label>
      </div>
    </div>
--- a/frontend/src/pages/LoginPage.tsx
+++ b/frontend/src/pages/LoginPage.tsx
@@ -44,7 +44,7 @@ export function LoginPageView({
  onSubmit,
 }: LoginPageViewProps) {
  return (
-    <div className="min-h-screen bg-gray-100 dark:bg-gray-800 dark:text-white">
+    <div className="min-h-screen bg-canvas text-content">
      <div className="flex w-full flex-wrap">
        <div className="flex w-full flex-col md:w-1/2">
          <div className="my-auto flex flex-col justify-center px-8 pt-8 md:justify-start md:px-24 md:pt-0 lg:px-32">
@@ -56,7 +56,7 @@ export function LoginPageView({
                    type="text"
                    value={username}
                    onChange={e => onUsernameChange(e.target.value)}
-                    className="w-full flex-1 appearance-none rounded-none border border-gray-300 bg-white px-4 py-2 text-base text-gray-700 shadow-sm placeholder:text-gray-400 focus:border-transparent focus:outline-none focus:ring-2 focus:ring-purple-600"
+                    className="w-full flex-1 appearance-none rounded-none border border-border bg-surface px-4 py-2 text-base text-content shadow-sm placeholder:text-content-subtle focus:border-transparent focus:outline-none focus:ring-2 focus:ring-primary-600"
                    placeholder="Username"
                    required
                    disabled={isLoading}
@@ -69,7 +69,7 @@ export function LoginPageView({
                    type="password"
                    value={password}
                    onChange={e => onPasswordChange(e.target.value)}
-                    className="w-full flex-1 appearance-none rounded-none border border-gray-300 bg-white px-4 py-2 text-base text-gray-700 shadow-sm placeholder:text-gray-400 focus:border-transparent focus:outline-none focus:ring-2 focus:ring-purple-600"
+                    className="w-full flex-1 appearance-none rounded-none border border-border bg-surface px-4 py-2 text-base text-content shadow-sm placeholder:text-content-subtle focus:border-transparent focus:outline-none focus:ring-2 focus:ring-primary-600"
                    placeholder="Password"
                    required
                    disabled={isLoading}
@@ -103,8 +103,8 @@ export function LoginPageView({
          </div>
        </div>
        <div className="relative hidden h-screen w-1/2 shadow-2xl md:block">
-          <div className="left-0 top-0 flex h-screen w-full items-center justify-center bg-gray-300 object-cover ease-in-out">
-            <span className="text-gray-500">AnthoLume</span>
+          <div className="left-0 top-0 flex h-screen w-full items-center justify-center bg-surface-strong object-cover ease-in-out">
+            <span className="text-content-muted">AnthoLume</span>
          </div>
        </div>
      </div>
--- a/frontend/src/pages/SettingsPage.tsx
+++ b/frontend/src/pages/SettingsPage.tsx
@@ -5,12 +5,21 @@ import { UserIcon, PasswordIcon, ClockIcon } from '../icons';
 import { Button } from '../components/Button';
 import { useToasts } from '../components/ToastContext';
 import { getErrorMessage } from '../utils/errors';
+import { useTheme } from '../theme/ThemeProvider';
+import type { ThemeMode } from '../utils/localSettings';
+
+const themeModes: Array<{ value: ThemeMode; label: string; description: string }> = [
+  { value: 'light', label: 'Light', description: 'Always use the light palette.' },
+  { value: 'dark', label: 'Dark', description: 'Always use the dark palette.' },
+  { value: 'system', label: 'System', description: 'Follow your device preference.' },
+];

 export default function SettingsPage() {
  const { data, isLoading } = useGetSettings();
  const updateSettings = useUpdateSettings();
  const settingsData = data?.status === 200 ? (data.data as SettingsResponse) : null;
  const { showInfo, showError } = useToasts();
+  const { themeMode, resolvedThemeMode, setThemeMode } = useTheme();

  const [password, setPassword] = useState('');
  const [newPassword, setNewPassword] = useState('');
@@ -33,7 +42,7 @@ export default function SettingsPage() {
    try {
      await updateSettings.mutateAsync({
        data: {
-          password: password,
+          password,
          new_password: newPassword,
        },
      });
@@ -51,7 +60,7 @@ export default function SettingsPage() {
    try {
      await updateSettings.mutateAsync({
        data: {
-          timezone: timezone,
+          timezone,
        },
      });
      showInfo('Timezone updated successfully');
@@ -64,13 +73,13 @@ export default function SettingsPage() {
    return (
      <div className="flex w-full flex-col gap-4 md:flex-row">
        <div>
-          <div className="flex flex-col items-center rounded bg-white p-4 shadow-lg md:w-60 lg:w-80 dark:bg-gray-700">
+          <div className="flex flex-col items-center rounded bg-surface p-4 shadow-lg md:w-60 lg:w-80">
            <div className="mb-4 size-16 rounded-full bg-gray-200 dark:bg-gray-600" />
            <div className="h-6 w-32 rounded bg-gray-200 dark:bg-gray-600" />
          </div>
        </div>
        <div className="flex grow flex-col gap-4">
-          <div className="flex flex-col gap-2 rounded bg-white p-4 shadow-lg dark:bg-gray-700">
+          <div className="flex flex-col gap-2 rounded bg-surface p-4 shadow-lg">
            <div className="mb-4 h-6 w-48 rounded bg-gray-200 dark:bg-gray-600" />
            <div className="flex gap-4">
              <div className="h-12 flex-1 rounded bg-gray-200 dark:bg-gray-600" />
@@ -78,14 +87,22 @@ export default function SettingsPage() {
              <div className="h-10 w-40 rounded bg-gray-200 dark:bg-gray-600" />
            </div>
          </div>
-          <div className="flex flex-col gap-2 rounded bg-white p-4 shadow-lg dark:bg-gray-700">
+          <div className="flex flex-col gap-2 rounded bg-surface p-4 shadow-lg">
            <div className="mb-4 h-6 w-48 rounded bg-gray-200 dark:bg-gray-600" />
            <div className="flex gap-4">
              <div className="h-12 flex-1 rounded bg-gray-200 dark:bg-gray-600" />
              <div className="h-10 w-40 rounded bg-gray-200 dark:bg-gray-600" />
            </div>
          </div>
-          <div className="flex flex-col rounded bg-white p-4 shadow-lg dark:bg-gray-700">
+          <div className="flex flex-col gap-2 rounded bg-surface p-4 shadow-lg">
+            <div className="mb-4 h-6 w-48 rounded bg-gray-200 dark:bg-gray-600" />
+            <div className="grid gap-3 md:grid-cols-3">
+              {themeModes.map(mode => (
+                <div key={mode.value} className="h-24 rounded bg-gray-200 dark:bg-gray-600" />
+              ))}
+            </div>
+          </div>
+          <div className="flex flex-col rounded bg-surface p-4 shadow-lg">
            <div className="mb-4 h-6 w-24 rounded bg-gray-200 dark:bg-gray-600" />
            <div className="mb-4 flex gap-4">
              <div className="h-6 flex-1 rounded bg-gray-200 dark:bg-gray-600" />
@@ -101,43 +118,41 @@ export default function SettingsPage() {

  return (
    <div className="flex w-full flex-col gap-4 md:flex-row">
-      {/* User Profile Card */}
      <div>
-        <div className="flex flex-col items-center rounded bg-white p-4 text-gray-500 shadow-lg md:w-60 lg:w-80 dark:bg-gray-700 dark:text-white">
+        <div className="flex flex-col items-center rounded bg-surface p-4 text-content-muted shadow-lg md:w-60 lg:w-80">
          <UserIcon size={60} />
-          <p className="text-lg">{settingsData?.user.username || 'N/A'}</p>
+          <p className="text-lg text-content">{settingsData?.user.username || 'N/A'}</p>
        </div>
      </div>

      <div className="flex grow flex-col gap-4">
-        {/* Change Password Form */}
-        <div className="flex grow flex-col gap-2 rounded bg-white p-4 text-gray-500 shadow-lg dark:bg-gray-700 dark:text-white">
-          <p className="mb-2 text-lg font-semibold">Change Password</p>
+        <div className="flex grow flex-col gap-2 rounded bg-surface p-4 text-content-muted shadow-lg">
+          <p className="mb-2 text-lg font-semibold text-content">Change Password</p>
          <form className="flex flex-col gap-4 lg:flex-row" onSubmit={handlePasswordSubmit}>
            <div className="flex grow flex-col">
              <div className="relative flex">
-                <span className="inline-flex items-center border-y border-l border-gray-300 bg-white px-3 text-sm text-gray-500 shadow-sm">
+                <span className="inline-flex items-center border-y border-l border-border bg-surface px-3 text-sm text-content-muted shadow-sm">
                  <PasswordIcon size={15} />
                </span>
                <input
                  type="password"
                  value={password}
                  onChange={e => setPassword(e.target.value)}
-                  className="w-full flex-1 appearance-none rounded-none border border-gray-300 bg-white px-4 py-2 text-base text-gray-700 shadow-sm placeholder:text-gray-400 focus:border-transparent focus:outline-none focus:ring-2 focus:ring-purple-600"
+                  className="w-full flex-1 appearance-none rounded-none border border-border bg-surface px-4 py-2 text-base text-content shadow-sm placeholder:text-content-subtle focus:border-transparent focus:outline-none focus:ring-2 focus:ring-primary-600"
                  placeholder="Password"
                />
              </div>
            </div>
            <div className="flex grow flex-col">
              <div className="relative flex">
-                <span className="inline-flex items-center border-y border-l border-gray-300 bg-white px-3 text-sm text-gray-500 shadow-sm">
+                <span className="inline-flex items-center border-y border-l border-border bg-surface px-3 text-sm text-content-muted shadow-sm">
                  <PasswordIcon size={15} />
                </span>
                <input
                  type="password"
                  value={newPassword}
                  onChange={e => setNewPassword(e.target.value)}
-                  className="w-full flex-1 appearance-none rounded-none border border-gray-300 bg-white px-4 py-2 text-base text-gray-700 shadow-sm placeholder:text-gray-400 focus:border-transparent focus:outline-none focus:ring-2 focus:ring-purple-600"
+                  className="w-full flex-1 appearance-none rounded-none border border-border bg-surface px-4 py-2 text-base text-content shadow-sm placeholder:text-content-subtle focus:border-transparent focus:outline-none focus:ring-2 focus:ring-primary-600"
                  placeholder="New Password"
                />
              </div>
@@ -150,18 +165,56 @@ export default function SettingsPage() {
          </form>
        </div>

-        {/* Change Timezone Form */}
-        <div className="flex grow flex-col gap-2 rounded bg-white p-4 text-gray-500 shadow-lg dark:bg-gray-700 dark:text-white">
-          <p className="mb-2 text-lg font-semibold">Change Timezone</p>
+        <div className="flex grow flex-col gap-2 rounded bg-surface p-4 text-content-muted shadow-lg">
+          <div className="flex items-center justify-between gap-4">
+            <div>
+              <p className="mb-1 text-lg font-semibold text-content">Appearance</p>
+              <p>
+                Active mode: <span className="font-medium text-content">{resolvedThemeMode}</span>
+              </p>
+            </div>
+          </div>
+          <div className="grid gap-3 md:grid-cols-3">
+            {themeModes.map(mode => {
+              const isSelected = themeMode === mode.value;
+
+              return (
+                <button
+                  key={mode.value}
+                  type="button"
+                  onClick={() => setThemeMode(mode.value)}
+                  className={`rounded border p-4 text-left transition-colors ${
+                    isSelected
+                      ? 'border-primary-500 bg-primary-50 text-content dark:bg-primary-100/20'
+                      : 'border-border bg-surface-muted text-content-muted hover:border-primary-300 hover:bg-surface'
+                  }`}
+                >
+                  <div className="mb-3 flex items-center justify-between">
+                    <span className="text-base font-semibold text-content">{mode.label}</span>
+                    <span
+                      className={`inline-flex size-4 rounded-full border ${
+                        isSelected ? 'border-primary-500 bg-primary-500' : 'border-border-strong'
+                      }`}
+                    />
+                  </div>
+                  <p className="text-sm">{mode.description}</p>
+                </button>
+              );
+            })}
+          </div>
+        </div>
+
+        <div className="flex grow flex-col gap-2 rounded bg-surface p-4 text-content-muted shadow-lg">
+          <p className="mb-2 text-lg font-semibold text-content">Change Timezone</p>
          <form className="flex flex-col gap-4 lg:flex-row" onSubmit={handleTimezoneSubmit}>
            <div className="relative flex grow">
-              <span className="inline-flex items-center border-y border-l border-gray-300 bg-white px-3 text-sm text-gray-500 shadow-sm">
+              <span className="inline-flex items-center border-y border-l border-border bg-surface px-3 text-sm text-content-muted shadow-sm">
                <ClockIcon size={15} />
              </span>
              <select
                value={timezone || 'UTC'}
                onChange={e => setTimezone(e.target.value)}
-                className="w-full flex-1 appearance-none rounded-none border border-gray-300 bg-white px-4 py-2 text-base text-gray-700 shadow-sm placeholder:text-gray-400 focus:border-transparent focus:outline-none focus:ring-2 focus:ring-purple-600"
+                className="w-full flex-1 appearance-none rounded-none border border-border bg-surface px-4 py-2 text-base text-content shadow-sm placeholder:text-content-subtle focus:border-transparent focus:outline-none focus:ring-2 focus:ring-primary-600"
              >
                <option value="UTC">UTC</option>
                <option value="America/New_York">America/New_York</option>
@@ -183,24 +236,23 @@ export default function SettingsPage() {
          </form>
        </div>

-        {/* Devices Table */}
-        <div className="flex grow flex-col rounded bg-white p-4 text-gray-500 shadow-lg dark:bg-gray-700 dark:text-white">
-          <p className="text-lg font-semibold">Devices</p>
-          <table className="min-w-full bg-white text-sm dark:bg-gray-700">
-            <thead className="text-gray-800 dark:text-gray-400">
+        <div className="flex grow flex-col rounded bg-surface p-4 text-content-muted shadow-lg">
+          <p className="text-lg font-semibold text-content">Devices</p>
+          <table className="min-w-full bg-surface text-sm">
+            <thead className="text-content-muted">
              <tr>
-                <th className="border-b border-gray-200 p-3 pl-0 text-left font-normal uppercase dark:border-gray-800">
+                <th className="border-b border-border p-3 pl-0 text-left font-normal uppercase">
                  Name
                </th>
-                <th className="border-b border-gray-200 p-3 text-left font-normal uppercase dark:border-gray-800">
+                <th className="border-b border-border p-3 text-left font-normal uppercase">
                  Last Sync
                </th>
-                <th className="border-b border-gray-200 p-3 text-left font-normal uppercase dark:border-gray-800">
+                <th className="border-b border-border p-3 text-left font-normal uppercase">
                  Created
                </th>
              </tr>
            </thead>
-            <tbody className="text-black dark:text-white">
+            <tbody className="text-content">
              {!settingsData?.devices || settingsData.devices.length === 0 ? (
                <tr>
                  <td className="p-3 text-center" colSpan={3}>
--- a/frontend/src/theme/ThemeProvider.tsx
+++ b/frontend/src/theme/ThemeProvider.tsx
@@ -0,0 +1,126 @@
+import {
+  createContext,
+  useCallback,
+  useContext,
+  useEffect,
+  useMemo,
+  useState,
+  type ReactNode,
+} from 'react';
+import { getThemeMode, setThemeMode, type ThemeMode } from '../utils/localSettings';
+
+export type ResolvedThemeMode = 'light' | 'dark';
+
+interface ThemeContextValue {
+  themeMode: ThemeMode;
+  resolvedThemeMode: ResolvedThemeMode;
+  setThemeMode: (themeMode: ThemeMode) => void;
+}
+
+const ThemeContext = createContext<ThemeContextValue | null>(null);
+
+function getSystemThemeMode(): ResolvedThemeMode {
+  if (typeof window === 'undefined') {
+    return 'light';
+  }
+
+  return window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
+}
+
+export function resolveThemeMode(themeMode: ThemeMode): ResolvedThemeMode {
+  return themeMode === 'system' ? getSystemThemeMode() : themeMode;
+}
+
+export function applyThemeMode(themeMode: ThemeMode): ResolvedThemeMode {
+  const resolvedThemeMode = resolveThemeMode(themeMode);
+
+  if (typeof document !== 'undefined') {
+    document.documentElement.classList.toggle('dark', resolvedThemeMode === 'dark');
+    document.documentElement.dataset.themeMode = themeMode;
+    document.documentElement.style.colorScheme = resolvedThemeMode;
+  }
+
+  return resolvedThemeMode;
+}
+
+export function initializeThemeMode(): ResolvedThemeMode {
+  return applyThemeMode(getThemeMode());
+}
+
+export function ThemeProvider({ children }: { children: ReactNode }) {
+  const [themeModeState, setThemeModeState] = useState<ThemeMode>(() => getThemeMode());
+  const [resolvedThemeMode, setResolvedThemeMode] = useState<ResolvedThemeMode>(() =>
+    resolveThemeMode(getThemeMode())
+  );
+
+  useEffect(() => {
+    setResolvedThemeMode(applyThemeMode(themeModeState));
+  }, [themeModeState]);
+
+  useEffect(() => {
+    if (typeof window === 'undefined') {
+      return undefined;
+    }
+
+    const mediaQueryList = window.matchMedia('(prefers-color-scheme: dark)');
+
+    const handleSystemThemeChange = () => {
+      if (themeModeState === 'system') {
+        setResolvedThemeMode(applyThemeMode('system'));
+      }
+    };
+
+    mediaQueryList.addEventListener('change', handleSystemThemeChange);
+    return () => {
+      mediaQueryList.removeEventListener('change', handleSystemThemeChange);
+    };
+  }, [themeModeState]);
+
+  useEffect(() => {
+    if (typeof window === 'undefined') {
+      return undefined;
+    }
+
+    const handleStorage = (event: StorageEvent) => {
+      if (event.key && event.key !== 'antholume:settings') {
+        return;
+      }
+
+      const nextThemeMode = getThemeMode();
+      setThemeModeState(nextThemeMode);
+      setResolvedThemeMode(applyThemeMode(nextThemeMode));
+    };
+
+    window.addEventListener('storage', handleStorage);
+    return () => {
+      window.removeEventListener('storage', handleStorage);
+    };
+  }, []);
+
+  const updateThemeMode = useCallback((nextThemeMode: ThemeMode) => {
+    setThemeMode(nextThemeMode);
+    setThemeModeState(nextThemeMode);
+    setResolvedThemeMode(applyThemeMode(nextThemeMode));
+  }, []);
+
+  const value = useMemo(
+    () => ({
+      themeMode: themeModeState,
+      resolvedThemeMode,
+      setThemeMode: updateThemeMode,
+    }),
+    [resolvedThemeMode, themeModeState, updateThemeMode]
+  );
+
+  return <ThemeContext.Provider value={value}>{children}</ThemeContext.Provider>;
+}
+
+export function useTheme() {
+  const context = useContext(ThemeContext);
+
+  if (!context) {
+    throw new Error('useTheme must be used within a ThemeProvider');
+  }
+
+  return context;
+}
--- a/frontend/src/utils/localSettings.ts
+++ b/frontend/src/utils/localSettings.ts
@@ -0,0 +1,66 @@
+export type ThemeMode = 'light' | 'dark' | 'system';
+export type DocumentsViewMode = 'grid' | 'list';
+
+const LOCAL_SETTINGS_KEY = 'antholume:settings';
+
+interface LocalSettings {
+  themeMode?: ThemeMode;
+  documentsViewMode?: DocumentsViewMode;
+}
+
+function canUseLocalStorage(): boolean {
+  return typeof window !== 'undefined' && typeof window.localStorage !== 'undefined';
+}
+
+function readLocalSettings(): LocalSettings {
+  if (!canUseLocalStorage()) {
+    return {};
+  }
+
+  const rawValue = window.localStorage.getItem(LOCAL_SETTINGS_KEY);
+  if (!rawValue) {
+    return {};
+  }
+
+  try {
+    const parsedValue = JSON.parse(rawValue);
+    return typeof parsedValue === 'object' && parsedValue !== null ? parsedValue : {};
+  } catch {
+    return {};
+  }
+}
+
+function writeLocalSettings(settings: LocalSettings): void {
+  if (!canUseLocalStorage()) {
+    return;
+  }
+
+  window.localStorage.setItem(LOCAL_SETTINGS_KEY, JSON.stringify(settings));
+}
+
+function updateLocalSettings(partialSettings: LocalSettings): void {
+  writeLocalSettings({
+    ...readLocalSettings(),
+    ...partialSettings,
+  });
+}
+
+export function getThemeMode(): ThemeMode {
+  const settings = readLocalSettings();
+  return settings.themeMode === 'light' || settings.themeMode === 'dark'
+    ? settings.themeMode
+    : 'system';
+}
+
+export function setThemeMode(themeMode: ThemeMode): void {
+  updateLocalSettings({ themeMode });
+}
+
+export function getDocumentsViewMode(): DocumentsViewMode {
+  const settings = readLocalSettings();
+  return settings.documentsViewMode === 'list' ? 'list' : 'grid';
+}
+
+export function setDocumentsViewMode(documentsViewMode: DocumentsViewMode): void {
+  updateLocalSettings({ documentsViewMode });
+}
--- a/frontend/tailwind.config.js
+++ b/frontend/tailwind.config.js
@@ -1,9 +1,51 @@
+const withOpacity = cssVariable => `rgb(var(${cssVariable}) / <alpha-value>)`;
+
+const buildScale = scaleName => ({
+  50: withOpacity(`--${scaleName}-50`),
+  100: withOpacity(`--${scaleName}-100`),
+  200: withOpacity(`--${scaleName}-200`),
+  300: withOpacity(`--${scaleName}-300`),
+  400: withOpacity(`--${scaleName}-400`),
+  500: withOpacity(`--${scaleName}-500`),
+  600: withOpacity(`--${scaleName}-600`),
+  700: withOpacity(`--${scaleName}-700`),
+  800: withOpacity(`--${scaleName}-800`),
+  900: withOpacity(`--${scaleName}-900`),
+  DEFAULT: withOpacity(`--${scaleName}-500`),
+  foreground: withOpacity(`--${scaleName}-foreground`),
+});
+
 /** @type {import('tailwindcss').Config} */
 export default {
  content: ['./src/**/*.{js,ts,jsx,tsx}'],
-  darkMode: 'media',
+  darkMode: 'class',
  theme: {
-    extend: {},
+    extend: {
+      colors: {
+        canvas: withOpacity('--canvas'),
+        surface: withOpacity('--surface'),
+        'surface-muted': withOpacity('--surface-muted'),
+        'surface-strong': withOpacity('--surface-strong'),
+        overlay: withOpacity('--overlay'),
+        content: withOpacity('--content'),
+        'content-muted': withOpacity('--content-muted'),
+        'content-subtle': withOpacity('--content-subtle'),
+        'content-inverse': withOpacity('--content-inverse'),
+        border: withOpacity('--border'),
+        'border-muted': withOpacity('--border-muted'),
+        'border-strong': withOpacity('--border-strong'),
+        white: withOpacity('--white'),
+        black: withOpacity('--black'),
+        gray: buildScale('neutral'),
+        purple: buildScale('primary'),
+        blue: buildScale('secondary'),
+        yellow: buildScale('warning'),
+        red: buildScale('error'),
+        primary: buildScale('primary'),
+        secondary: buildScale('secondary'),
+        tertiary: buildScale('tertiary'),
+      },
+    },
  },
  plugins: [],
 };