修复图标选择器被编辑器工具栏遮挡的问题

- 提升标签/图标行的z-index(z-20→z-30)使其高于工具栏
- 降低工具栏z-index(z-20→z-10)拉开层级差距
- 修复动画结束帧transform值为none，避免残留transform创建额外stacking context

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/globals.css

@@ -135,7 +135,7 @@
 
   to {
     opacity: 1;
-    transform: translateY(0) scale(1);
+    transform: none;
   }
 }
 

src/app/page.tsx

@@ -276,7 +276,7 @@ export default function Home() {
                   </div>
                 </div>
 
-                <div className="ui-enter-delayed relative z-20 mb-6 flex flex-wrap items-center gap-2">
+                <div className="ui-enter-delayed relative z-30 mb-6 flex flex-wrap items-center gap-2">
                   {activePage.tags?.map((tag) => {
                     const colors = getTagColor(tag);
                     return (

src/components/editor/toolbar.tsx

@@ -112,7 +112,7 @@ export function Toolbar({ editor, onToggleAI, onExport }: ToolbarProps) {
     ];
 
     return (
-        <div className="sticky top-0 z-20 -mx-1 mb-2 flex items-center gap-1 overflow-x-auto rounded-xl border border-border/60 bg-background/80 p-1 shadow-[0_1px_0_hsl(var(--border)/0.45),0_10px_20px_hsl(var(--background)/0.24)] backdrop-blur-md no-scrollbar supports-[backdrop-filter]:bg-background/68">
+        <div className="sticky top-0 z-10 -mx-1 mb-2 flex items-center gap-1 overflow-x-auto rounded-xl border border-border/60 bg-background/80 p-1 shadow-[0_1px_0_hsl(var(--border)/0.45),0_10px_20px_hsl(var(--background)/0.24)] backdrop-blur-md no-scrollbar supports-[backdrop-filter]:bg-background/68">
             {items.map((item, index) =>
                 item.divider ? (
                     <div key={index} className="mx-1 h-6 w-px bg-border/80" />