feat: improve UI components with consistent styling and layout adjustments

web/app/dashboard/ai-workflows/_components/workflow-node-palette.tsx

@@ -12,17 +12,17 @@ export function WorkflowNodePalette({
   onAddNode: (spec: AIWorkflowNodeSpec) => void
 }) {
   return (
-    <aside className="relative z-50 flex w-60 shrink-0 flex-col border-r bg-muted/20">
+    <aside className="absolute left-3 top-3 z-50 flex max-h-[calc(100%-1.5rem)] w-64 shrink-0 flex-col overflow-hidden rounded-md border bg-background/95 shadow-sm backdrop-blur">
       <div className="border-b px-3 py-2">
-        <div className="text-sm font-medium">节点</div>
+        <div className="text-xs font-medium text-muted-foreground">节点</div>
       </div>
-      <div className="min-h-0 flex-1 overflow-y-auto p-2">
+      <div className="min-h-0 flex-1 overflow-y-auto p-1.5">
         <div className="space-y-1">
           {nodeSpecs.map((spec) => (
             <button
               key={spec.type}
               type="button"
-              className="flex w-full items-start gap-2 rounded-md border bg-background px-2 py-2 text-left text-sm hover:bg-muted"
+              className="flex w-full items-start gap-2 rounded-sm px-2 py-2 text-left text-sm hover:bg-muted"
               onClick={() => onAddNode(spec)}
             >
               <PlusIcon className="mt-0.5 size-3.5 shrink-0 text-muted-foreground" />