Fix taiji fish eyes and expose theme toggle on mobile.

Correct yin-yang eye colors with contrast strokes, and show light/dark switch in mobile header with Chinese labels.

Co-authored-by: Cursor <cursoragent@cursor.com>

components/mode-toggle.tsx

@@ -17,22 +17,28 @@ export function ModeToggle() {
   return (
     <DropdownMenu>
       <DropdownMenuTrigger asChild>
-        <Button variant="ghost" size="sm" className="hidden sm:block">
-          <Sun size={22} strokeWidth={1.5} className="dark:hidden" />
-          <MoonStar size={22} strokeWidth={1.5} className="hidden dark:block" />
+        <Button
+          variant="ghost"
+          size="icon"
+          className="h-9 w-9 shrink-0"
+          aria-label="切换亮色 / 暗色"
+        >
+          <Sun size={20} strokeWidth={1.5} className="dark:hidden" />
+          <MoonStar size={20} strokeWidth={1.5} className="hidden dark:block" />
         </Button>
       </DropdownMenuTrigger>
-      <DropdownMenuContent align="start">
+      <DropdownMenuContent align="end">
         <DropdownMenuItem onClick={() => setTheme("light")}>
-          <Sun size={20} strokeWidth={1.5} className="mr-2" />
-          Light
+          <Sun size={18} strokeWidth={1.5} className="mr-2" />
+          亮色
         </DropdownMenuItem>
         <DropdownMenuItem onClick={() => setTheme("dark")}>
-          <MoonStar size={20} strokeWidth={1.5} className="mr-2" />
-          Dark
+          <MoonStar size={18} strokeWidth={1.5} className="mr-2" />
+          暗色
         </DropdownMenuItem>
         <DropdownMenuItem onClick={() => setTheme("system")}>
-          <Laptop2 size={20} strokeWidth={1.5} className="mr-2" /> System
+          <Laptop2 size={18} strokeWidth={1.5} className="mr-2" />
+          跟随系统
         </DropdownMenuItem>
       </DropdownMenuContent>
     </DropdownMenu>