diff --git a/components/ai-cad/ai-cad-workbench.tsx b/components/ai-cad/ai-cad-workbench.tsx
index a29aa4373..c3b9517cf 100644
--- a/components/ai-cad/ai-cad-workbench.tsx
+++ b/components/ai-cad/ai-cad-workbench.tsx
@@ -1998,11 +1998,11 @@ function AiCadPanelResizeHandle({ className }: { className?: string }) {
   return (
     <PanelResizeHandle
       className={cn(
-        "group relative flex shrink-0 items-center justify-center bg-transparent outline-none data-[panel-group-direction=horizontal]:mx-1.5 data-[panel-group-direction=vertical]:my-1.5 data-[panel-group-direction=vertical]:h-2 data-[panel-group-direction=horizontal]:w-2 data-[panel-group-direction=horizontal]:cursor-col-resize data-[panel-group-direction=vertical]:cursor-row-resize",
+        "group relative flex shrink-0 items-center justify-center bg-transparent outline-none data-[panel-group-direction=vertical]:h-px data-[panel-group-direction=horizontal]:w-px data-[panel-group-direction=horizontal]:cursor-col-resize data-[panel-group-direction=vertical]:cursor-row-resize",
         className
       )}
     >
-      <div className="rounded-full bg-[#d5cfc2] transition group-hover:bg-[#beb6a6] data-[panel-group-direction=horizontal]:h-16 data-[panel-group-direction=vertical]:h-[2px] data-[panel-group-direction=horizontal]:w-[2px] data-[panel-group-direction=vertical]:w-16 group-data-[resize-handle-state=drag]:bg-[#8f8573]" />
+      <div className="bg-[#e9e3d7] transition group-hover:bg-[#d7cfbf] data-[panel-group-direction=horizontal]:h-full data-[panel-group-direction=vertical]:h-px data-[panel-group-direction=horizontal]:w-px data-[panel-group-direction=vertical]:w-full group-data-[resize-handle-state=drag]:bg-[#bdb4a3]" />
     </PanelResizeHandle>
   );
 }
@@ -2022,10 +2022,10 @@ function AiCadCollapsedPanel({
     <div className="h-full min-h-0">
       <div
         className={cn(
-          "flex h-full rounded-[18px] border border-[#d9d2c4] bg-[#fbfaf5] text-[#221f18] shadow-[0_1px_0_rgba(255,255,255,0.9)]",
+          "flex h-full border border-[#ece7db] bg-white text-[#221f18]",
           direction === "horizontal"
-            ? "flex-col items-center justify-center gap-3 px-3 py-5"
-            : "items-center justify-between gap-4 px-4 py-3"
+            ? "flex-col items-center justify-center gap-3 px-2 py-4"
+            : "items-center justify-between gap-4 px-3 py-2"
         )}
       >
         <div
@@ -2034,11 +2034,11 @@ function AiCadCollapsedPanel({
             direction === "horizontal" && "flex-col text-center"
           )}
         >
-          <Icon className="h-5 w-5 text-[#6a6558]" />
-          <div className="font-medium text-[#221f18] text-sm">{title}</div>
+          <Icon className="h-4 w-4 text-[#6a6558]" />
+          <div className="font-medium text-[#221f18] text-xs">{title}</div>
         </div>
         <Button
-          className="gap-2 rounded-xl border-[#d9d2c4] bg-white text-[#221f18] transition-all duration-150 ease-out hover:bg-[#f2eee6]"
+          className="gap-2 rounded-md border-[#ddd7ca] bg-white text-[#221f18] transition-all duration-150 ease-out hover:bg-[#f6f2ea]"
           onClick={onExpand}
           size="sm"
           type="button"
@@ -2070,24 +2070,22 @@ function AiCadRailButton({
       <span
         className={cn(
           "-left-2 -translate-y-1/2 absolute top-1/2 h-6 w-0.5 rounded-full bg-transparent transition-all duration-150 ease-out",
-          active && "bg-[#31df86] shadow-[0_0_8px_rgba(49,223,134,0.45)]"
+          active && "bg-[#31df86]"
         )}
       />
       <button
         className={cn(
-          "flex w-11 flex-col items-center gap-1 rounded-2xl border px-0 py-2.5 transition-all duration-150 ease-out",
+          "flex h-10 w-10 items-center justify-center rounded-md border transition-all duration-150 ease-out",
           active
-            ? "border-[#b7dcc5] bg-[#ecfbf2] text-[#173225] shadow-[0_10px_24px_rgba(49,223,134,0.08)]"
-            : "border-[#ddd7ca] bg-white/88 text-[#6f695d] hover:border-[#cfc7b6] hover:bg-white hover:text-[#221f18]"
+            ? "border-[#b7dcc5] bg-[#eefcf4] text-[#173225]"
+            : "border-transparent bg-transparent text-[#6f695d] hover:border-[#e4dece] hover:bg-[#faf7ef] hover:text-[#221f18]"
         )}
         onClick={onClick}
         title={label}
         type="button"
       >
         <Icon className="h-4 w-4" />
-        <span className="font-medium text-[9px] uppercase leading-none tracking-[0.18em]">
-          {shortLabel}
-        </span>
+        <span className="sr-only">{shortLabel}</span>
       </button>
     </div>
   );
@@ -2105,7 +2103,7 @@ function AiCadToolbarGroup({
   return (
     <div
       className={cn(
-        "flex flex-wrap items-center gap-2 rounded-xl border border-[#ddd6c8] bg-white px-2.5 py-2 shadow-[0_1px_0_rgba(255,255,255,0.9)]",
+        "flex flex-wrap items-center gap-2 border border-[#e6e0d3] bg-white px-2 py-1.5",
         className
       )}
     >
@@ -2118,7 +2116,7 @@ function AiCadToolbarGroup({
   );
 }
 
-function AiCadMessageActionButton({
+function _AiCadMessageActionButton({
   icon: Icon,
   label,
   onClick,
@@ -2139,7 +2137,7 @@ function AiCadMessageActionButton({
   );
 }
 
-function AiCadStatusChip({
+function _AiCadStatusChip({
   label,
   tone = "neutral",
   value,
@@ -2405,21 +2403,26 @@ export function AiCadWorkbench() {
   }, [activeWorkspaceId]);
 
   useEffect(() => {
+    const hasActiveVersion = Boolean(activeVersionId || versions.length > 0);
+
     if (
-      hasAutoCollapsedExplorerRef.current ||
       panelDirection !== "horizontal" ||
       isLoadingWorkspaceList ||
       !hasHydratedFromStorage ||
-      versions.length > 0 ||
       !historyPanelRef.current
     ) {
       return;
     }
 
-    hasAutoCollapsedExplorerRef.current = true;
-    historyPanelRef.current.collapse();
-    setIsHistoryPanelCollapsed(true);
+    if (!hasActiveVersion) {
+      hasAutoCollapsedExplorerRef.current = true;
+      historyPanelRef.current.collapse();
+      setIsHistoryPanelCollapsed(true);
+    } else if (versions.length > 0 && hasAutoCollapsedExplorerRef.current) {
+      hasAutoCollapsedExplorerRef.current = false;
+    }
   }, [
+    activeVersionId,
     hasHydratedFromStorage,
     isLoadingWorkspaceList,
     panelDirection,
@@ -2684,7 +2687,7 @@ export function AiCadWorkbench() {
     semanticCodeDiffInsights.length > 0
       ? semanticCodeDiffInsights
       : activeVersionSemanticInsights;
-  const followUpSuggestions = buildFollowUpSuggestions({
+  const _followUpSuggestions = buildFollowUpSuggestions({
     activeVersion,
     activeParentVersion,
     previewSourceVersion,
@@ -2705,7 +2708,7 @@ export function AiCadWorkbench() {
   const activeWorkspaceName = activeWorkspace?.name || "AI-CAD 工作台";
   const normalizedWorkspaceName = normalizeWorkspaceTitle(activeWorkspaceName);
   const shouldForceTreeCollapsed =
-    !activeVersion && activeLeftPanelView === "tree";
+    panelDirection === "horizontal" && !activeVersion;
   const isWorkspaceActionDisabled =
     isSubmitting || isCreatingWorkspace || isDeletingWorkspace;
   const canDeleteActiveWorkspace =
@@ -3511,26 +3514,26 @@ export function AiCadWorkbench() {
   }
 
   return (
-    <div className="flex min-h-svh flex-col overflow-hidden bg-[#f2efe7] text-[#201c16]">
-      <div className="border-[#ddd7ca] border-b bg-[#faf8f2]">
-        <div className="flex flex-wrap items-center gap-3 px-4 py-3">
+    <div className="flex min-h-svh flex-col overflow-hidden bg-[#f8f7f3] text-[#201c16]">
+      <div className="border-[#e6e0d3] border-b bg-white">
+        <div className="flex min-h-14 flex-wrap items-center gap-3 px-3 py-2">
           <a
-            className="inline-flex items-center gap-2 rounded-xl border border-[#d8d2c4] bg-white px-3 py-1.5 text-[#423d33] text-[13px] transition-all duration-150 ease-out hover:bg-[#f4f1e8]"
+            className="inline-flex h-10 items-center gap-2 rounded-[10px] border border-[#e2dccf] bg-white px-3 text-[#423d33] text-[13px] transition-all duration-150 ease-out hover:bg-[#faf7ef]"
             href="/"
           >
             <ChevronLeft className="h-4 w-4" />
             返回首页
           </a>
-          <div className="flex items-center gap-2 rounded-xl border border-[#d8d2c4] bg-white px-2 py-1.5">
-            <div className="flex h-7 w-9 items-center justify-center rounded-md bg-[#42ef95] font-semibold text-[#0f2318] text-[11px]">
+          <div className="flex h-10 items-center gap-2 rounded-[10px] border border-[#e2dccf] bg-white px-3">
+            <div className="flex h-8 w-10 items-center justify-center rounded-md bg-[#42ef95] font-semibold text-[#0f2318] text-[11px]">
               AI
             </div>
-            <span className="font-medium text-[#201c16] text-[13px]">
+            <span className="font-medium text-[#201c16] text-[14px]">
               AI-CAD Studio
             </span>
           </div>
           <button
-            className="flex min-w-[240px] flex-1 items-center gap-2 rounded-xl border border-[#d8d2c4] bg-white px-4 py-2 text-left text-[#3e392f]"
+            className="flex h-10 min-w-[240px] flex-1 items-center gap-2 rounded-[10px] border border-[#e2dccf] bg-white px-4 text-left text-[#3e392f]"
             onClick={() => setActiveLeftPanelView("project")}
             type="button"
           >
@@ -3540,26 +3543,26 @@ export function AiCadWorkbench() {
             <ChevronDown className="ml-auto h-4 w-4 text-[#827b6d]" />
           </button>
           <button
-            className="inline-flex items-center gap-2 rounded-xl border border-[#d8d2c4] bg-white px-3 py-1.5 text-[#423d33] text-[13px] transition-all duration-150 ease-out hover:bg-[#f4f1e8]"
+            className="inline-flex h-10 items-center gap-2 rounded-[10px] border border-[#e2dccf] bg-white px-3 text-[#423d33] text-[13px] transition-all duration-150 ease-out hover:bg-[#faf7ef]"
             type="button"
           >
             <Grid3X3 className="h-4 w-4" />
             Commands
           </button>
           <button
-            className="hidden items-center gap-2 rounded-xl border border-[#d8d2c4] bg-white px-3 py-1.5 text-[#423d33] text-[13px] transition-all duration-150 ease-out hover:bg-[#f4f1e8] lg:inline-flex"
+            className="hidden h-10 items-center gap-2 rounded-[10px] border border-[#e2dccf] bg-white px-3 text-[#423d33] text-[13px] transition-all duration-150 ease-out hover:bg-[#faf7ef] lg:inline-flex"
             type="button"
           >
             <ArrowUpRight className="h-4 w-4" />
             Share
           </button>
-          <div className="flex h-8 w-8 items-center justify-center rounded-full border border-[#d8d2c4] bg-[#7a4d2a] text-sm text-white">
+          <div className="flex h-10 w-10 items-center justify-center rounded-full bg-[#8b572a] text-sm text-white">
             AI
           </div>
         </div>
 
         {(workspaceSyncError || workspaceOperationError) && (
-          <div className="border-[#e6e0d3] border-t px-4 py-2.5">
+          <div className="border-[#e6e0d3] border-t px-3 py-2">
             <div className="flex flex-wrap gap-3 text-sm leading-6">
               {workspaceSyncError ? (
                 <p className="text-rose-700">
@@ -3578,7 +3581,7 @@ export function AiCadWorkbench() {
 
       <div className="min-h-0 flex-1 overflow-hidden">
         <div className="flex h-full min-h-0">
-          <div className="flex w-16 shrink-0 flex-col items-center justify-between border-[#ddd7ca] border-r bg-[#f8f5ee] px-2 py-3">
+          <div className="flex w-14 shrink-0 flex-col items-center justify-between border-[#e6e0d3] border-r bg-white px-1.5 py-3">
             <div className="flex flex-col items-center gap-2">
               <AiCadRailButton
                 active={
@@ -3638,55 +3641,73 @@ export function AiCadWorkbench() {
             <div className="flex flex-col items-center gap-2">
               {primaryDownloadEntry ? (
                 <a
-                  className="flex w-11 flex-col items-center gap-1 rounded-2xl border border-[#ddd7ca] bg-white px-0 py-2.5 text-[#6f695d] transition-all duration-150 ease-out hover:border-[#cfc7b6] hover:bg-[#f6f2ea] hover:text-[#221f18]"
+                  className="flex h-10 w-10 items-center justify-center rounded-md border border-[#e4dece] bg-white text-[#6f695d] transition-all duration-150 ease-out hover:bg-[#faf7ef] hover:text-[#221f18]"
                   href={primaryDownloadEntry.url}
                   rel="noreferrer"
                   target="_blank"
                   title="导出当前版本"
                 >
                   <Download className="h-4 w-4" />
-                  <span className="font-medium text-[9px] uppercase leading-none tracking-[0.18em]">
-                    Export
-                  </span>
+                  <span className="sr-only">Export</span>
                 </a>
               ) : (
                 <button
-                  className="flex w-11 cursor-not-allowed flex-col items-center gap-1 rounded-2xl border border-[#ddd7ca] bg-white px-0 py-2.5 text-[#b8b0a2]"
+                  className="flex h-10 w-10 cursor-not-allowed items-center justify-center rounded-md border border-[#ece7dc] bg-white text-[#b8b0a2]"
                   disabled
                   title="暂无可导出文件"
                   type="button"
                 >
                   <Download className="h-4 w-4" />
-                  <span className="font-medium text-[9px] uppercase leading-none tracking-[0.18em]">
-                    Export
-                  </span>
+                  <span className="sr-only">Export</span>
                 </button>
               )}
               <button
-                className="flex w-11 flex-col items-center gap-1 rounded-2xl border border-[#ddd7ca] bg-white px-0 py-2.5 text-[#6f695d] transition-all duration-150 ease-out hover:border-[#cfc7b6] hover:bg-[#f6f2ea] hover:text-[#221f18]"
+                className="flex h-10 w-10 items-center justify-center rounded-md border border-[#e4dece] bg-white text-[#6f695d] transition-all duration-150 ease-out hover:bg-[#faf7ef] hover:text-[#221f18]"
                 onClick={handleResetWorkbench}
                 title="重置当前工作台"
                 type="button"
               >
                 <RotateCcw className="h-4 w-4" />
-                <span className="font-medium text-[9px] uppercase leading-none tracking-[0.18em]">
-                  Reset
-                </span>
+                <span className="sr-only">Reset</span>
               </button>
             </div>
           </div>
 
           <div className="flex min-h-0 flex-1 flex-col overflow-hidden">
-            <div className="border-[#ddd7ca] border-b bg-[#fdfbf7] px-4 py-3">
+            <div className="border-[#e6e0d3] border-b bg-white px-4 py-2.5">
               <div className="flex flex-wrap items-center justify-between gap-2">
-                <div className="flex flex-wrap items-center gap-2" />
-                <div className="flex flex-wrap items-center gap-2 text-[#7f7768] text-[11px]">
-                  <span>
+                <div className="flex flex-wrap items-center gap-2">
+                  <button
+                    className="inline-flex h-9 items-center gap-2 rounded-[10px] border border-[#e2dccf] bg-white px-3 text-[#383329] text-[13px] transition hover:bg-[#faf7ef]"
+                    type="button"
+                  >
+                    <WandSparkles className="h-4 w-4 text-[#31df86]" />
+                    Start Design
+                  </button>
+                  <Badge className="rounded-full border-[#e2dccf] bg-white px-3 py-1 text-[#5f594d]">
+                    {generationProvider === "kittycad-cad"
+                      ? "KittyCAD / Zoo CAD"
+                      : "Tripo3D"}
+                  </Badge>
+                  <Badge className="rounded-full border-[#e2dccf] bg-white px-3 py-1 text-[#5f594d]">
                     {activeVersion
                       ? `Focus V${activeVersion.versionNumber}`
                       : "Ready for first pass"}
-                  </span>
+                  </Badge>
+                  <Badge
+                    className={cn(
+                      "rounded-full px-3 py-1",
+                      workspaceSyncState === "synced"
+                        ? "border-emerald-200 bg-emerald-50 text-emerald-700"
+                        : "border-[#e2dccf] bg-white text-[#5f594d]"
+                    )}
+                  >
+                    {workspaceSyncState === "synced" ? "Synced" : "Syncing"}
+                  </Badge>
+                </div>
+                <div className="flex flex-wrap items-center gap-2 text-[#7f7768] text-[11px]">
                   <span>{versions.length} versions</span>
+                  <span>{completedCount} done</span>
                   <span>
                     {hasPendingTasks
                       ? `${pendingTaskCount} task active`
@@ -3695,14 +3716,14 @@ export function AiCadWorkbench() {
                 </div>
               </div>
 
-              <div className="mt-2.5 flex flex-wrap items-start gap-2">
+              <div className="mt-2 flex flex-wrap items-start gap-2">
                 <AiCadToolbarGroup label="Mode">
                   <button
                     className={cn(
-                      "inline-flex items-center gap-2 rounded-xl border px-3 py-1.5 text-[13px] transition-all duration-150 ease-out",
+                      "inline-flex h-9 items-center gap-2 rounded-[10px] border px-3 text-[13px] transition-all duration-150 ease-out",
                       activeResultTab === "preview"
                         ? "border-[#bfd9c9] bg-[#ecfbf2] text-[#173225]"
-                        : "border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#f4f1e8]"
+                        : "border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#faf7ef]"
                     )}
                     onClick={() => {
                       resultPanelRef.current?.expand();
@@ -3715,10 +3736,10 @@ export function AiCadWorkbench() {
                   </button>
                   <button
                     className={cn(
-                      "inline-flex items-center gap-2 rounded-xl border px-3 py-1.5 text-[13px] transition-all duration-150 ease-out",
+                      "inline-flex h-9 items-center gap-2 rounded-[10px] border px-3 text-[13px] transition-all duration-150 ease-out",
                       activeResultTab === "code"
                         ? "border-[#bfd9c9] bg-[#ecfbf2] text-[#173225]"
-                        : "border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#f4f1e8]"
+                        : "border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#faf7ef]"
                     )}
                     onClick={() => {
                       resultPanelRef.current?.expand();
@@ -3734,10 +3755,10 @@ export function AiCadWorkbench() {
                 <AiCadToolbarGroup label="Display">
                   <button
                     className={cn(
-                      "inline-flex h-8 w-8 items-center justify-center rounded-xl border transition-all duration-150 ease-out",
+                      "inline-flex h-9 w-9 items-center justify-center rounded-[10px] border transition-all duration-150 ease-out",
                       viewerSettings.showGrid
                         ? "border-[#bfd9c9] bg-[#ecfbf2] text-[#173225]"
-                        : "border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#f4f1e8]"
+                        : "border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#faf7ef]"
                     )}
                     onClick={() =>
                       setViewerSettings((current) => ({
@@ -3752,10 +3773,10 @@ export function AiCadWorkbench() {
                   </button>
                   <button
                     className={cn(
-                      "inline-flex h-8 w-8 items-center justify-center rounded-xl border transition-all duration-150 ease-out",
+                      "inline-flex h-9 w-9 items-center justify-center rounded-[10px] border transition-all duration-150 ease-out",
                       viewerSettings.autoRotate
                         ? "border-[#bfd9c9] bg-[#ecfbf2] text-[#173225]"
-                        : "border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#f4f1e8]"
+                        : "border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#faf7ef]"
                     )}
                     onClick={() =>
                       setViewerSettings((current) => ({
@@ -3770,10 +3791,10 @@ export function AiCadWorkbench() {
                   </button>
                   <button
                     className={cn(
-                      "inline-flex h-8 w-8 items-center justify-center rounded-xl border transition-all duration-150 ease-out",
+                      "inline-flex h-9 w-9 items-center justify-center rounded-[10px] border transition-all duration-150 ease-out",
                       viewerSettings.wireframe
                         ? "border-[#bfd9c9] bg-[#ecfbf2] text-[#173225]"
-                        : "border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#f4f1e8]"
+                        : "border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#faf7ef]"
                     )}
                     onClick={() =>
                       setViewerSettings((current) => ({
@@ -3806,18 +3827,18 @@ export function AiCadWorkbench() {
               </div>
             </div>
 
-            <div className="min-h-0 flex-1 overflow-y-auto bg-[#f2efe7] p-3">
+            <div className="min-h-0 flex-1 overflow-hidden bg-white">
               <PanelGroup
                 autoSaveId={`ai-cad-panel-layout:${panelDirection}`}
-                className="flex h-full min-h-[780px]"
+                className="flex h-full min-h-[720px]"
                 direction={panelDirection}
               >
                 <Panel
                   className="order-5 min-h-0"
-                  collapsedSize={panelDirection === "horizontal" ? 11 : 12}
+                  collapsedSize={panelDirection === "horizontal" ? 8 : 12}
                   collapsible
-                  defaultSize={29}
-                  minSize={panelDirection === "horizontal" ? 24 : 22}
+                  defaultSize={panelDirection === "horizontal" ? 34 : 29}
+                  minSize={panelDirection === "horizontal" ? 28 : 22}
                   onCollapse={() => setIsConversationPanelCollapsed(true)}
                   onExpand={() => setIsConversationPanelCollapsed(false)}
                   order={3}
@@ -3831,78 +3852,35 @@ export function AiCadWorkbench() {
                       title="AI-CAD Agent"
                     />
                   ) : (
-                    <Card className="flex h-full min-h-0 flex-col rounded-[22px] border-[#ddd7ca] bg-[#fbfaf5] text-[#201c16] shadow-none">
-                      <CardHeader className="space-y-2.5 border-[#e6e0d3] border-b bg-[#f8f5ee] pb-2.5">
-                        <div className="flex items-start justify-between gap-4">
-                          <div>
-                            <CardTitle className="flex items-center gap-2 text-[15px]">
-                              <BrainCircuit className="h-4 w-4 text-[#6f695d]" />
-                              AI-CAD Agent
-                            </CardTitle>
-                            <CardDescription className="mt-1 text-[#7f7768] text-[12px]">
-                              Continuous design thread for the active version.
-                            </CardDescription>
-                          </div>
-                          <div className="flex items-center gap-2">
-                            <Badge className="rounded-[8px] border-[#ddd7ca] bg-white text-[#5f594d] text-[11px]">
-                              Agent
-                            </Badge>
-                            <button
-                              className="inline-flex h-8 w-8 items-center justify-center rounded-xl border border-[#ddd7ca] bg-white text-[#6f695d] transition-all duration-150 ease-out hover:bg-[#f4f1e8] hover:text-[#201c16]"
-                              type="button"
-                            >
-                              <MoreHorizontal className="h-4 w-4" />
-                            </button>
-                            <button
-                              className="inline-flex h-8 w-8 items-center justify-center rounded-xl border border-[#ddd7ca] bg-white text-[#6f695d] transition-all duration-150 ease-out hover:bg-[#f4f1e8] hover:text-[#201c16]"
-                              onClick={() =>
-                                conversationPanelRef.current?.collapse()
-                              }
-                              type="button"
-                            >
-                              <ChevronRight className="h-4 w-4" />
-                            </button>
-                          </div>
+                    <div className="flex h-full min-h-0 flex-col border-[#e6e0d3] border-l bg-white text-[#201c16]">
+                      <div className="flex h-12 items-center justify-between border-[#e6e0d3] border-b px-4">
+                        <div className="flex items-center gap-2 font-medium text-[15px]">
+                          <BrainCircuit className="h-4 w-4 text-[#6f695d]" />
+                          AI-CAD Agent
                         </div>
+                        <div className="flex items-center gap-2">
+                          <button
+                            className="inline-flex h-8 w-8 items-center justify-center rounded-md text-[#6f695d] transition hover:bg-[#f6f2ea] hover:text-[#201c16]"
+                            type="button"
+                          >
+                            <MoreHorizontal className="h-4 w-4" />
+                          </button>
+                          <button
+                            className="inline-flex h-8 w-8 items-center justify-center rounded-md text-[#6f695d] transition hover:bg-[#f6f2ea] hover:text-[#201c16]"
+                            onClick={() =>
+                              conversationPanelRef.current?.collapse()
+                            }
+                            type="button"
+                          >
+                            <ChevronRight className="h-4 w-4" />
+                          </button>
+                        </div>
+                      </div>
 
-                        {activeVersion ? (
-                          <div className="rounded-2xl border border-[#ddd7ca] bg-white px-3 py-2">
-                            <div className="flex flex-wrap items-center justify-between gap-2">
-                              <div className="flex flex-wrap items-center gap-2">
-                                <Badge className="rounded-[8px] border-[#ddd7ca] bg-[#f7f3ea] text-[#5f594d] text-[11px]">
-                                  Session Context
-                                </Badge>
-                                <Badge className="rounded-[8px] border-[#ddd7ca] bg-[#f7f3ea] text-[#5f594d] text-[11px]">
-                                  Focus V{activeVersion.versionNumber}
-                                </Badge>
-                              </div>
-                              <div className="flex flex-wrap items-center gap-2 text-[#7f7768] text-[11px]">
-                                <span>
-                                  {getProviderLabel(activeVersion.provider)}
-                                </span>
-                                <span>
-                                  {getStatusLabel(activeVersion.status)}
-                                </span>
-                                <span>
-                                  {activeVersion.generationMode === "iterate"
-                                    ? "Iterative"
-                                    : "Initial"}
-                                </span>
-                              </div>
-                            </div>
-                            <p className="mt-1.5 text-[#6d665a] text-[12px] leading-5">
-                              {activeVersion.generationMode === "iterate"
-                                ? `当前已经沿着 V${activeVersion.versionNumber} 进入连续修改模式。`
-                                : `当前焦点在 V${activeVersion.versionNumber}。`}
-                            </p>
-                          </div>
-                        ) : null}
-                      </CardHeader>
-
-                      <CardContent className="flex min-h-0 flex-1 flex-col p-0">
-                        <ScrollArea className="min-h-0 flex-1 px-3.5 py-3.5">
+                      <ScrollArea className="min-h-0 flex-1">
+                        <div className="flex min-h-full flex-col justify-end px-5 py-5">
                           {activeVersion || messages.length > 1 ? (
-                            <div className="flex min-h-full flex-col justify-end gap-3">
+                            <div className="space-y-4">
                               {messages.map((message) => {
                                 const linkedVersion = message.versionId
                                   ? findVersionById(versions, message.versionId)
@@ -3911,106 +3889,113 @@ export function AiCadWorkbench() {
                                 return (
                                   <div
                                     className={cn(
-                                      "rounded-2xl border px-3 py-2.5 shadow-none transition-all duration-150 ease-out",
+                                      "flex",
                                       message.role === "user"
-                                        ? "ml-auto max-w-[84%] border-[#ddd7ca] bg-white text-[#201c16]"
-                                        : "w-full border-[#e2ddd1] bg-[#f7f5ef] text-[#201c16]"
+                                        ? "justify-end"
+                                        : "justify-start"
                                     )}
                                     key={message.id}
                                   >
-                                    <div className="flex items-center justify-between gap-3">
-                                      <div className="flex items-center gap-2 text-[#8a8272] text-[10px] uppercase tracking-[0.18em]">
+                                    <div
+                                      className={cn(
+                                        "max-w-[86%]",
+                                        message.role === "user"
+                                          ? "rounded-[8px] border border-[#e5dfd2] bg-white px-4 py-3"
+                                          : "rounded-[10px] bg-[#f3f2ee] px-4 py-4"
+                                      )}
+                                    >
+                                      <div className="mb-2 flex items-center gap-2 text-[#8a8272] text-[11px]">
                                         {message.role === "user" ? (
-                                          <>
-                                            <WandSparkles className="h-3.5 w-3.5" />
-                                            你
-                                          </>
+                                          <span>你</span>
                                         ) : (
-                                          <>
-                                            <Bot className="h-3.5 w-3.5" />
-                                            AI-CAD Agent
-                                          </>
+                                          <span>AI-CAD</span>
                                         )}
                                         <span>
                                           {formatClockTime(message.createdAt)}
                                         </span>
-                                      </div>
-                                      {message.role !== "user" &&
-                                      message.state ? (
-                                        <Badge className="rounded-[8px] border-[#ddd7ca] bg-white text-[#5f594d] text-[10px] uppercase tracking-[0.16em]">
-                                          {getMessageStateLabel(message.state)}
-                                        </Badge>
-                                      ) : null}
-                                    </div>
-
-                                    {linkedVersion ? (
-                                      <div className="mt-2 flex flex-wrap items-center gap-1.5">
-                                        <Badge className="border-[#ddd7ca] bg-white text-[#5f594d]">
-                                          V{linkedVersion.versionNumber}
-                                        </Badge>
-                                        <Badge
-                                          className={cn(
-                                            "border px-2 py-0 font-medium text-[11px]",
-                                            getStatusBadgeClass(
-                                              linkedVersion.status
-                                            )
-                                          )}
-                                        >
-                                          {getStatusLabel(linkedVersion.status)}
-                                        </Badge>
-                                      </div>
-                                    ) : null}
-
-                                    <div className="mt-2 text-[13px] leading-[1.65]">
-                                      {message.content}
-                                    </div>
-
-                                    {linkedVersion ? (
-                                      <div className="mt-3 flex flex-wrap items-center gap-1.5 border-[#e6e0d3] border-t pt-2.5">
-                                        <AiCadMessageActionButton
-                                          icon={ArrowUpRight}
-                                          label={`聚焦 V${linkedVersion.versionNumber}`}
-                                          onClick={() =>
-                                            setActiveVersionId(linkedVersion.id)
-                                          }
-                                        />
-                                        {canIterateKittyCadVersion(
-                                          linkedVersion
-                                        ) ? (
-                                          <AiCadMessageActionButton
-                                            icon={GitBranch}
-                                            label="继续修改"
-                                            onClick={() =>
-                                              handleFocusVersionForIteration(
-                                                linkedVersion
-                                              )
-                                            }
-                                          />
+                                        {message.role !== "user" &&
+                                        message.state ? (
+                                          <span className="text-[#6e685d]">
+                                            {getMessageStateLabel(
+                                              message.state
+                                            )}
+                                          </span>
                                         ) : null}
                                       </div>
-                                    ) : null}
+                                      <div className="text-[15px] leading-7">
+                                        {message.content}
+                                      </div>
+                                      {linkedVersion ? (
+                                        <div className="mt-3 flex flex-wrap items-center gap-2">
+                                          <button
+                                            className="inline-flex items-center gap-1 rounded-md border border-[#ddd7ca] bg-white px-2.5 py-1 text-[#5f594d] text-xs transition hover:bg-[#faf7ef] hover:text-[#201c16]"
+                                            onClick={() =>
+                                              setActiveVersionId(
+                                                linkedVersion.id
+                                              )
+                                            }
+                                            type="button"
+                                          >
+                                            V{linkedVersion.versionNumber}
+                                          </button>
+                                          {canIterateKittyCadVersion(
+                                            linkedVersion
+                                          ) ? (
+                                            <button
+                                              className="inline-flex items-center gap-1 rounded-md border border-[#ddd7ca] bg-white px-2.5 py-1 text-[#5f594d] text-xs transition hover:bg-[#faf7ef] hover:text-[#201c16]"
+                                              onClick={() =>
+                                                handleFocusVersionForIteration(
+                                                  linkedVersion
+                                                )
+                                              }
+                                              type="button"
+                                            >
+                                              继续修改
+                                            </button>
+                                          ) : null}
+                                        </div>
+                                      ) : null}
+                                    </div>
                                   </div>
                                 );
                               })}
                             </div>
                           ) : (
-                            <div className="flex min-h-full flex-col justify-end">
-                              <div className="rounded-2xl border border-[#e2ddd1] bg-[#f7f5ef] px-5 py-4 text-[#4d473d]">
-                                <p className="text-[15px] leading-7">
+                            <div className="space-y-5">
+                              <div className="text-center text-[#7f7768] text-[14px]">
+                                9 seconds ago
+                              </div>
+                              <div className="flex items-start gap-3">
+                                <div className="mt-1 flex h-8 w-8 items-center justify-center rounded-md bg-[#31df86] text-[#102315]">
+                                  <Bot className="h-4 w-4" />
+                                </div>
+                                <div className="max-w-[92%] rounded-[10px] bg-[#f3f2ee] px-5 py-4 text-[#3d382f] text-[15px] leading-7">
                                   Try requesting a model, ask engineering
                                   questions, or let's explore ideas.
-                                </p>
+                                </div>
                               </div>
                             </div>
                           )}
-                        </ScrollArea>
+                        </div>
+                      </ScrollArea>
 
-                        <div className="border-[#e6e0d3] border-t bg-[#f8f5ee] p-3.5">
-                          {activeVersion ? (
-                            <div className="mb-2.5 flex flex-wrap items-center gap-2">
-                              <Badge className="border-[#ddd7ca] bg-white text-[#5f594d]">
-                                生成引擎
-                              </Badge>
+                      <div className="border-[#e6e0d3] border-t bg-white px-4 py-4">
+                        <div className="rounded-[8px] border border-[#d7d0c1] bg-white">
+                          <Textarea
+                            className="min-h-[120px] resize-none border-0 bg-transparent px-4 py-4 text-[#201c16] text-[15px] placeholder:text-[#9a9385] focus-visible:ring-0 focus-visible:ring-offset-0"
+                            onChange={(event) => setPrompt(event.target.value)}
+                            onKeyDown={(event) => {
+                              if (event.key === "Enter" && !event.shiftKey) {
+                                event.preventDefault();
+                                swallowAsync(handleSubmit());
+                              }
+                            }}
+                            placeholder="Create a gear with 10 teeth and use sensible defaults for everything else..."
+                            value={prompt}
+                          />
+
+                          <div className="flex flex-wrap items-center justify-between gap-3 border-[#ece6d9] border-t px-4 py-3">
+                            <div className="flex flex-wrap items-center gap-2">
                               <Select
                                 onValueChange={(value) =>
                                   setGenerationProvider(
@@ -4019,160 +4004,62 @@ export function AiCadWorkbench() {
                                 }
                                 value={generationProvider}
                               >
-                                <SelectTrigger className="h-9 w-[220px] border-[#ddd7ca] bg-white text-[#201c16]">
+                                <SelectTrigger className="h-10 min-w-[136px] rounded-[8px] border-[#ddd7ca] bg-white text-[#201c16]">
                                   <SelectValue placeholder="选择生成引擎" />
                                 </SelectTrigger>
                                 <SelectContent>
                                   <SelectItem value="kittycad-cad">
-                                    KittyCAD / Zoo CAD
+                                    Fast
                                   </SelectItem>
                                   <SelectItem value="tripo-3d">
-                                    Tripo3D（当前回退）
+                                    Tripo3D
                                   </SelectItem>
                                 </SelectContent>
                               </Select>
-                              {generationProvider === "tripo-3d" ? (
-                                <>
-                                  <Badge className="border-[#ddd7ca] bg-white text-[#5f594d]">
-                                    Tripo 模型版本
-                                  </Badge>
-                                  <Select
-                                    onValueChange={setModelVersion}
-                                    value={modelVersion}
-                                  >
-                                    <SelectTrigger className="h-9 w-[220px] border-[#ddd7ca] bg-white text-[#201c16]">
-                                      <SelectValue placeholder="选择模型版本" />
-                                    </SelectTrigger>
-                                    <SelectContent>
-                                      {MODEL_VERSION_OPTIONS.map((option) => (
-                                        <SelectItem key={option} value={option}>
-                                          {option}
-                                        </SelectItem>
-                                      ))}
-                                    </SelectContent>
-                                  </Select>
-                                </>
-                              ) : (
-                                <Badge className="border-emerald-200 bg-emerald-50 text-emerald-700">
-                                  输出 GLB / STEP / KCL
-                                </Badge>
-                              )}
-                            </div>
-                          ) : null}
-
-                          {activeVersion ? (
-                            <div className="mb-2.5 rounded-2xl border border-[#ddd7ca] bg-white px-3.5 py-3">
-                              <div className="flex flex-wrap items-center justify-between gap-3">
-                                <div className="text-[#8a8272] text-xs uppercase tracking-[0.16em]">
-                                  Suggested Next Edits
-                                </div>
-                                {semanticFocusInsights.length > 0 ? (
-                                  <div className="flex flex-wrap gap-2">
-                                    {semanticFocusInsights.map((insight) => (
-                                      <Badge
-                                        className="rounded-md border-[#ddd7ca] bg-[#f7f3ea] text-[#5f594d]"
-                                        key={insight.key}
-                                      >
-                                        {insight.shortLabel}
-                                      </Badge>
-                                    ))}
-                                  </div>
-                                ) : null}
-                              </div>
-                              <div className="mt-3 flex flex-wrap gap-2">
-                                {followUpSuggestions.slice(0, 3).map((item) => (
-                                  <button
-                                    className="rounded-xl border border-[#ddd7ca] bg-[#f7f3ea] px-3 py-1.5 text-left text-[#5f594d] text-xs transition-all duration-150 ease-out hover:bg-[#efe9de]"
-                                    key={item}
-                                    onClick={() => setPrompt(item)}
-                                    type="button"
-                                  >
-                                    {item}
-                                  </button>
-                                ))}
-                              </div>
-                            </div>
-                          ) : null}
-
-                          <div className="rounded-2xl border border-[#ddd7ca] bg-white p-3 shadow-[0_1px_0_rgba(255,255,255,0.9)]">
-                            <Textarea
-                              className="min-h-[128px] resize-none border-0 bg-transparent px-0 py-0 text-[#201c16] placeholder:text-[#9a9385] focus-visible:ring-0 focus-visible:ring-offset-0"
-                              onChange={(event) =>
-                                setPrompt(event.target.value)
-                              }
-                              onKeyDown={(event) => {
-                                if (event.key === "Enter" && !event.shiftKey) {
-                                  event.preventDefault();
-                                  swallowAsync(handleSubmit());
-                                }
-                              }}
-                              placeholder="Create a tabletop 25 mm thick with 1 mm chamfers..."
-                              value={prompt}
-                            />
-
-                            <div className="mt-3 flex flex-wrap items-center justify-between gap-3 border-[#e6e0d3] border-t pt-3">
-                              <div className="flex flex-wrap items-center gap-2">
-                                <Select
-                                  onValueChange={(value) =>
-                                    setGenerationProvider(
-                                      value as CadGenerationProvider
-                                    )
-                                  }
-                                  value={generationProvider}
-                                >
-                                  <SelectTrigger className="h-10 min-w-[148px] rounded-xl border-[#ddd7ca] bg-white text-[#201c16]">
-                                    <SelectValue placeholder="选择生成引擎" />
-                                  </SelectTrigger>
-                                  <SelectContent>
-                                    <SelectItem value="kittycad-cad">
-                                      Fast
-                                    </SelectItem>
-                                    <SelectItem value="tripo-3d">
-                                      Tripo3D
-                                    </SelectItem>
-                                  </SelectContent>
-                                </Select>
-                                <Button
-                                  className="h-8 w-8 rounded-xl border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#f4f1e8] hover:text-[#201c16]"
-                                  disabled
-                                  size="icon"
-                                  type="button"
-                                  variant="outline"
-                                >
-                                  <Paperclip className="h-4 w-4" />
-                                </Button>
-                                <Button
-                                  className="h-8 w-8 rounded-xl border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#f4f1e8] hover:text-[#201c16]"
-                                  disabled
-                                  size="icon"
-                                  type="button"
-                                  variant="outline"
-                                >
-                                  <Camera className="h-4 w-4" />
-                                </Button>
-                              </div>
-
                               <Button
-                                className="h-10 w-10 rounded-xl border border-[#2ccf78] bg-[#31df86] p-0 text-[#102315] transition-all duration-150 ease-out hover:bg-[#2ed57f]"
-                                disabled={isSubmitDisabled}
-                                onClick={() => swallowAsync(handleSubmit())}
+                                className="h-10 w-10 rounded-[8px] border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#faf7ef] hover:text-[#201c16]"
+                                disabled
+                                size="icon"
                                 type="button"
+                                variant="outline"
                               >
-                                {isSubmitting ? (
-                                  <Loader2 className="h-4 w-4 animate-spin" />
-                                ) : (
-                                  <Send className="h-4 w-4" />
-                                )}
+                                <Paperclip className="h-4 w-4" />
+                              </Button>
+                              <Button
+                                className="h-10 w-10 rounded-[8px] border-[#ddd7ca] bg-white text-[#5f594d] hover:bg-[#faf7ef] hover:text-[#201c16]"
+                                disabled
+                                size="icon"
+                                type="button"
+                                variant="outline"
+                              >
+                                <Camera className="h-4 w-4" />
                               </Button>
                             </div>
 
-                            <p className="mt-3 text-[#8a8272] text-xs leading-5">
-                              AI-CAD 可能出错。请始终核对尺寸、约束和几何结果。
-                            </p>
+                            <Button
+                              className="h-10 w-10 rounded-[8px] border border-[#2ccf78] bg-[#31df86] p-0 text-[#102315] transition-all duration-150 ease-out hover:bg-[#2ed57f]"
+                              disabled={isSubmitDisabled}
+                              onClick={() => swallowAsync(handleSubmit())}
+                              type="button"
+                            >
+                              {isSubmitting ? (
+                                <Loader2 className="h-4 w-4 animate-spin" />
+                              ) : (
+                                <Send className="h-4 w-4" />
+                              )}
+                            </Button>
                           </div>
                         </div>
-                      </CardContent>
-                    </Card>
+                        <div className="mt-2 flex items-center justify-between text-[#9a9385] text-xs">
+                          <span>
+                            {generationProvider === "kittycad-cad"
+                              ? "Fast"
+                              : "Tripo3D"}
+                          </span>
+                          <span>AI-CAD 可能出错，请始终核对结果。</span>
+                        </div>
+                      </div>
+                    </div>
                   )}
                 </Panel>
 
@@ -4180,10 +4067,10 @@ export function AiCadWorkbench() {
 
                 <Panel
                   className="order-1 min-h-0"
-                  collapsedSize={panelDirection === "horizontal" ? 11 : 12}
+                  collapsedSize={panelDirection === "horizontal" ? 0 : 12}
                   collapsible
-                  defaultSize={19}
-                  minSize={panelDirection === "horizontal" ? 16 : 18}
+                  defaultSize={18}
+                  minSize={panelDirection === "horizontal" ? 14 : 18}
                   onCollapse={() => setIsHistoryPanelCollapsed(true)}
                   onExpand={() => setIsHistoryPanelCollapsed(false)}
                   order={1}
@@ -4203,8 +4090,8 @@ export function AiCadWorkbench() {
                       }
                     />
                   ) : activeLeftPanelView === "project" ? (
-                    <Card className="flex h-full min-h-0 flex-col rounded-[22px] border-[#ddd7ca] bg-[#fbfaf5] text-[#201c16] shadow-none">
-                      <CardHeader className="border-[#e6e0d3] border-b bg-[#f8f5ee] pb-2.5">
+                    <Card className="flex h-full min-h-0 flex-col rounded-none border-0 border-[#e6e0d3] border-r bg-white text-[#201c16] shadow-none">
+                      <CardHeader className="border-[#e6e0d3] border-b bg-white pb-2.5">
                         <CardTitle className="flex items-center gap-2 text-[15px]">
                           <FolderOpen className="h-4 w-4 text-[#6f695d]" />
                           Project Explorer
@@ -4438,8 +4325,8 @@ export function AiCadWorkbench() {
                       </CardContent>
                     </Card>
                   ) : (
-                    <Card className="flex h-full min-h-0 flex-col rounded-[22px] border-[#ddd7ca] bg-[#fbfaf5] text-[#201c16] shadow-none">
-                      <CardHeader className="border-[#e6e0d3] border-b bg-[#f8f5ee] pb-2.5">
+                    <Card className="flex h-full min-h-0 flex-col rounded-none border-0 border-[#e6e0d3] border-r bg-white text-[#201c16] shadow-none">
+                      <CardHeader className="border-[#e6e0d3] border-b bg-white pb-2.5">
                         <CardTitle className="flex items-center gap-2 text-[15px]">
                           <History className="h-4 w-4 text-[#6f695d]" />
                           Feature Tree
@@ -4996,24 +4883,24 @@ export function AiCadWorkbench() {
                       title="建模画布"
                     />
                   ) : (
-                    <Card className="flex h-full min-h-0 flex-col rounded-[22px] border-[#ddd7ca] bg-[#fbfaf5] text-[#201c16] shadow-none">
-                      <CardHeader
+                    <div className="flex h-full min-h-0 flex-col bg-white text-[#201c16]">
+                      <div
                         className={cn(
-                          "border-[#e6e0d3] border-b bg-[#f8f5ee] pb-3",
-                          !activeVersion && "px-5 py-2.5"
+                          "flex items-center justify-between border-[#e6e0d3] border-b px-4 py-3",
+                          !activeVersion && "min-h-12"
                         )}
                       >
                         <div className="flex items-start justify-between gap-4">
                           <div>
-                            <CardTitle className="flex items-center gap-2 text-base">
+                            <div className="flex items-center gap-2 font-medium text-[15px]">
                               <Orbit className="h-4 w-4 text-[#6f695d]" />
                               {activeVersion ? "建模画布" : "Canvas"}
-                            </CardTitle>
-                            <CardDescription className="mt-1 text-[#7f7768]">
+                            </div>
+                            <div className="mt-1 text-[#7f7768] text-[12px]">
                               {activeVersion
-                                ? "把中间区域收成更接近官方的大画布，预览优先，代码与对照放到下层。"
+                                ? "Preview-first canvas for the active model."
                                 : "The center canvas stays focused on the current model."}
-                            </CardDescription>
+                            </div>
                           </div>
                           {activeVersion ? (
                             <Badge className="rounded-md border-[#ddd7ca] bg-white text-[#5f594d]">
@@ -5021,9 +4908,9 @@ export function AiCadWorkbench() {
                             </Badge>
                           ) : null}
                         </div>
-                      </CardHeader>
+                      </div>
 
-                      <CardContent className="min-h-0 flex-1 overflow-hidden p-0">
+                      <div className="min-h-0 flex-1 overflow-hidden p-0">
                         {activeVersion ? (
                           <ScrollArea className="h-full">
                             <div className="space-y-4 p-4">
@@ -6000,125 +5887,48 @@ export function AiCadWorkbench() {
                             </div>
                           </ScrollArea>
                         ) : (
-                          <div className="relative flex h-full min-h-0 flex-col bg-[#fcfbf7]">
-                            <div className="flex items-center justify-between border-[#e6e0d3] border-b bg-white/80 px-5 py-3">
-                              <div className="flex items-center gap-2 text-[#7f7768] text-[11px] uppercase tracking-[0.18em]">
-                                <span>Design Canvas</span>
-                                <span>Ready for first pass</span>
-                              </div>
-                              <div className="flex items-center gap-2">
-                                <button
-                                  className="inline-flex h-8 w-8 items-center justify-center rounded-xl border border-[#ddd7ca] bg-white text-[#5f594d] transition-all duration-150 ease-out hover:bg-[#f4f1e8] hover:text-[#201c16]"
-                                  onClick={() =>
-                                    setViewerSettings((current) => ({
-                                      ...current,
-                                      showGrid: !current.showGrid,
-                                    }))
-                                  }
-                                  title="切换网格"
-                                  type="button"
-                                >
-                                  <Grid3X3 className="h-4 w-4" />
-                                </button>
-                                <button
-                                  className="inline-flex h-8 w-8 items-center justify-center rounded-xl border border-[#ddd7ca] bg-white text-[#5f594d] transition-all duration-150 ease-out hover:bg-[#f4f1e8] hover:text-[#201c16]"
-                                  onClick={() =>
-                                    setViewerSettings((current) => ({
-                                      ...current,
-                                      autoRotate: !current.autoRotate,
-                                    }))
-                                  }
-                                  title="切换自动旋转"
-                                  type="button"
-                                >
-                                  <RotateCcw className="h-4 w-4" />
-                                </button>
-                              </div>
-                            </div>
-
+                          <div className="relative flex h-full min-h-0 flex-col bg-white">
                             <div className="relative min-h-0 flex-1 overflow-hidden">
-                              <div className="absolute inset-0 bg-[radial-gradient(circle_at_center,rgba(255,255,255,0.94),rgba(247,243,234,0.88))]" />
-                              <div className="-translate-x-1/2 absolute top-[16%] left-1/2 h-[68%] w-px bg-[#d8d1c5]" />
-                              <div className="-translate-y-1/2 absolute top-1/2 left-[14%] h-px w-[72%] bg-[#d8d1c5]" />
-                              <div className="-translate-x-1/2 absolute top-[22%] left-1/2 h-[56%] w-[42%] rounded-[999px] border border-[#ebe5d9]" />
-                              <div className="absolute right-6 bottom-6 rounded-full border border-[#d9d2c5] bg-white/92 px-4 py-3 shadow-sm">
-                                <div className="grid h-[78px] w-[78px] place-items-center rounded-full border border-[#e6e0d3] bg-[#faf7f1] text-[#7f7768] text-[11px]">
-                                  <div className="text-center leading-4">
-                                    <div>Top</div>
-                                    <div>Front</div>
-                                    <div>Right</div>
-                                  </div>
+                              <div className="absolute inset-0 bg-[linear-gradient(180deg,#ffffff_0%,#fcfaf5_100%)]" />
+                              <div className="-translate-x-1/2 absolute top-[12%] left-1/2 h-[72%] w-px bg-[#ddd6c9]" />
+                              <div className="-translate-y-1/2 absolute top-1/2 left-[8%] h-px w-[74%] bg-[#ddd6c9]" />
+                              <div className="-translate-x-1/2 absolute top-[22%] left-1/2 h-[56%] w-[42%] rounded-[999px] border border-[#efe8db]" />
+                              <div className="absolute right-8 bottom-8 flex h-[92px] w-[92px] items-center justify-center rounded-full border border-[#ddd7ca] bg-[#f6f3eb] text-[#7f7768] text-[11px] shadow-sm">
+                                <div className="text-center leading-4">
+                                  <div>Top</div>
+                                  <div>Front</div>
+                                  <div>Right</div>
                                 </div>
                               </div>
-                              <div className="absolute inset-x-0 bottom-[18%] flex justify-center px-6">
-                                <div className="rounded-2xl border border-[#e1dace] bg-white/90 px-5 py-3 text-center shadow-sm">
-                                  <div className="font-medium text-[#201c16] text-sm">
-                                    Start a design to create geometry
-                                  </div>
-                                  <p className="mt-1 text-[#7f7768] text-xs leading-5">
-                                    从右侧直接描述零件、尺寸和约束，画布会在这里保持当前模型。
-                                  </p>
+                              <div className="absolute inset-x-0 bottom-10 flex justify-center px-6">
+                                <div className="text-center text-[#948d7f] text-[13px]">
+                                  从右侧输入设计意图，模型会直接出现在画布中。
                                 </div>
                               </div>
                             </div>
                           </div>
                         )}
-                      </CardContent>
-                    </Card>
+                      </div>
+                    </div>
                   )}
                 </Panel>
               </PanelGroup>
             </div>
 
-            <div className="border-[#ddd7ca] border-t bg-[#faf8f2] px-3 py-2">
+            <div className="border-[#e6e0d3] border-t bg-white px-4 py-2">
               <div className="flex flex-wrap items-center justify-between gap-3">
-                <div className="flex flex-wrap items-center gap-2">
-                  <AiCadStatusChip
-                    label="Engine"
-                    value={getProviderLabel(generationProvider)}
-                  />
-                  <AiCadStatusChip
-                    label="Focus"
-                    value={
-                      activeVersion
-                        ? `V${activeVersion.versionNumber}`
-                        : "No focus"
-                    }
-                  />
-                  <AiCadStatusChip
-                    label="State"
-                    tone={
-                      hasPendingTasks
-                        ? "pending"
-                        : activeVersion?.status === "success"
-                          ? "success"
-                          : "neutral"
-                    }
-                    value={
-                      activeVersion
-                        ? getStatusLabel(activeVersion.status)
-                        : "Ready to prompt"
-                    }
-                  />
-                  <AiCadStatusChip
-                    label="View"
-                    value={
-                      activeResultTab === "preview" ? "3D preview" : "KCL view"
-                    }
-                  />
-                  <AiCadStatusChip
-                    label="Env"
-                    value={viewerSettings.envPreset}
-                  />
-                  <AiCadStatusChip
-                    label="Tasks"
-                    tone={hasPendingTasks ? "warning" : "neutral"}
-                    value={
-                      hasPendingTasks
-                        ? `${pendingTaskCount} active`
-                        : "Workspace idle"
-                    }
-                  />
+                <div className="flex flex-wrap items-center gap-4 text-[#7f7768] text-xs">
+                  <span>{getProviderLabel(generationProvider)}</span>
+                  <span>
+                    {activeVersion
+                      ? `V${activeVersion.versionNumber} · ${getStatusLabel(activeVersion.status)}`
+                      : "Ready for first pass"}
+                  </span>
+                  <span>
+                    {hasPendingTasks
+                      ? `${pendingTaskCount} active task`
+                      : "Workspace stable"}
+                  </span>
                 </div>
                 <div className="flex flex-wrap items-center gap-4 text-[#7f7768] text-xs">
                   <span>No selection</span>