refactor: align QR code tool with Calculate/Media blueprint

- QRCodeGenerator: lg:grid-cols-5 layout (2/5 options, 3/5 preview);
  full viewport height; mobile Configure|Preview glass pill tabs
- QRInput: remove shadcn Textarea/Card; native <textarea> in glass panel
  section; character counter in monospace
- QROptions: remove shadcn Card/Label/Input/Button/Select; EC level as
  4 pill buttons with recovery % label; native color inputs + pickers;
  transparent toggle as small pill; keep shadcn Slider for margin
- QRPreview: remove shadcn Card/Button/Skeleton/ToggleGroup/Tooltip/Empty;
  glass card fills full height; PNG button with inline size pill group
  (256/512/1k/2k); empty state and pulse skeleton match other tools

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

components/qrcode/QRCodeGenerator.tsx

@@ -9,8 +9,11 @@ import { decodeQRFromUrl, updateQRUrl, getQRShareableUrl } from '@/lib/qrcode/ur
 import { downloadBlob } from '@/lib/media/utils/fileUtils';
 import { debounce } from '@/lib/utils/debounce';
 import { toast } from 'sonner';
+import { cn } from '@/lib/utils/cn';
 import type { ErrorCorrectionLevel, ExportSize } from '@/types/qrcode';
 
+type MobileTab = 'configure' | 'preview';
+
 export function QRCodeGenerator() {
   const [text, setText] = React.useState('https://kit.pivoine.art');
   const [errorCorrection, setErrorCorrection] = React.useState<ErrorCorrectionLevel>('M');
@@ -20,6 +23,7 @@ export function QRCodeGenerator() {
   const [exportSize, setExportSize] = React.useState<ExportSize>(512);
   const [svgString, setSvgString] = React.useState('');
   const [isGenerating, setIsGenerating] = React.useState(false);
+  const [mobileTab, setMobileTab] = React.useState<MobileTab>('configure');
 
   // Load state from URL on mount
   React.useEffect(() => {
@@ -37,11 +41,7 @@ export function QRCodeGenerator() {
   const generate = React.useMemo(
     () =>
       debounce(async (t: string, ec: ErrorCorrectionLevel, fg: string, bg: string, m: number) => {
-        if (!t) {
-          setSvgString('');
-          setIsGenerating(false);
-          return;
-        }
+        if (!t) { setSvgString(''); setIsGenerating(false); return; }
         setIsGenerating(true);
         try {
           const svg = await generateSvg(t, ec, fg, bg, m);
@@ -57,13 +57,11 @@ export function QRCodeGenerator() {
     [],
   );
 
-  // Regenerate on changes
   React.useEffect(() => {
     generate(text, errorCorrection, foregroundColor, backgroundColor, margin);
     updateQRUrl(text, errorCorrection, foregroundColor, backgroundColor, margin);
   }, [text, errorCorrection, foregroundColor, backgroundColor, margin, generate]);
 
-  // Export: PNG download
   const handleDownloadPng = async () => {
     if (!text) return;
     try {
@@ -71,50 +69,67 @@ export function QRCodeGenerator() {
       const res = await fetch(dataUrl);
       const blob = await res.blob();
       downloadBlob(blob, `qrcode-${Date.now()}.png`);
-    } catch {
-      toast.error('Failed to export PNG');
-    }
+    } catch { toast.error('Failed to export PNG'); }
   };
 
-  // Export: SVG download
   const handleDownloadSvg = () => {
     if (!svgString) return;
     const blob = new Blob([svgString], { type: 'image/svg+xml' });
     downloadBlob(blob, `qrcode-${Date.now()}.svg`);
   };
 
-  // Copy image to clipboard
   const handleCopyImage = async () => {
     if (!text) return;
     try {
       const dataUrl = await generateDataUrl(text, errorCorrection, foregroundColor, backgroundColor, margin, exportSize);
       const res = await fetch(dataUrl);
       const blob = await res.blob();
-      await navigator.clipboard.write([
-        new ClipboardItem({ 'image/png': blob }),
-      ]);
+      await navigator.clipboard.write([new ClipboardItem({ 'image/png': blob })]);
       toast.success('Image copied to clipboard!');
-    } catch {
-      toast.error('Failed to copy image');
-    }
+    } catch { toast.error('Failed to copy image'); }
   };
 
-  // Share URL
   const handleShare = async () => {
     const shareUrl = getQRShareableUrl(text, errorCorrection, foregroundColor, backgroundColor, margin);
     try {
       await navigator.clipboard.writeText(shareUrl);
       toast.success('Shareable URL copied!');
-    } catch {
-      toast.error('Failed to copy URL');
-    }
+    } catch { toast.error('Failed to copy URL'); }
   };
 
   return (
-    <div className="grid grid-cols-1 lg:grid-cols-3 gap-6 items-stretch lg:max-h-[800px]">
-      {/* Left Column - Input and Options */}
-      <div className="lg:col-span-1 space-y-6 overflow-y-auto custom-scrollbar">
+    <div className="flex flex-col gap-4">
+
+      {/* ── Mobile tab switcher ─────────────────────────────── */}
+      <div className="flex lg:hidden glass rounded-xl p-1 gap-1">
+        {(['configure', 'preview'] as MobileTab[]).map((t) => (
+          <button
+            key={t}
+            onClick={() => setMobileTab(t)}
+            className={cn(
+              'flex-1 py-2.5 rounded-lg text-sm font-medium capitalize transition-all',
+              mobileTab === t
+                ? 'bg-primary text-primary-foreground shadow-sm'
+                : 'text-muted-foreground hover:text-foreground'
+            )}
+          >
+            {t === 'configure' ? 'Configure' : 'Preview'}
+          </button>
+        ))}
+      </div>
+
+      {/* ── Main layout ─────────────────────────────────────── */}
+      <div
+        className="grid grid-cols-1 lg:grid-cols-5 gap-4"
+        style={{ height: 'calc(100svh - 220px)', minHeight: '620px' }}
+      >
+
+        {/* Left: Input + Options */}
+        <div className={cn('lg:col-span-2 flex flex-col overflow-hidden', mobileTab !== 'configure' && 'hidden lg:flex')}>
+          <div className="glass rounded-xl p-4 flex flex-col flex-1 min-h-0 overflow-hidden">
+            <div className="flex-1 min-h-0 overflow-y-auto scrollbar-thin scrollbar-thumb-primary/20 scrollbar-track-transparent pr-0.5 space-y-5">
               <QRInput value={text} onChange={setText} />
+              <div className="border-t border-border/25" />
               <QROptions
                 errorCorrection={errorCorrection}
                 foregroundColor={foregroundColor}
@@ -126,9 +141,11 @@ export function QRCodeGenerator() {
                 onMarginChange={setMargin}
               />
             </div>
+          </div>
+        </div>
 
-      {/* Right Column - Preview */}
-      <div className="lg:col-span-2 h-full">
+        {/* Right: Preview */}
+        <div className={cn('lg:col-span-3 flex flex-col overflow-hidden', mobileTab !== 'preview' && 'hidden lg:flex')}>
           <QRPreview
             svgString={svgString}
             isGenerating={isGenerating}
@@ -141,5 +158,6 @@ export function QRCodeGenerator() {
           />
         </div>
       </div>
+    </div>
   );
 }

components/qrcode/QRInput.tsx

@@ -1,34 +1,29 @@
 'use client';
 
-import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
-import { Textarea } from '@/components/ui/textarea';
+const MAX_LENGTH = 2048;
 
 interface QRInputProps {
   value: string;
   onChange: (value: string) => void;
 }
 
-const MAX_LENGTH = 2048;
-
 export function QRInput({ value, onChange }: QRInputProps) {
   return (
-    <Card>
-      <CardHeader>
-        <CardTitle>Text</CardTitle>
-      </CardHeader>
-      <CardContent className="space-y-2">
-        <Textarea
+    <div>
+      <span className="text-[10px] font-semibold text-muted-foreground uppercase tracking-widest block mb-2">
+        Content
+      </span>
+      <textarea
         value={value}
         onChange={(e) => onChange(e.target.value)}
-          placeholder="Enter text or URL..."
+        placeholder="Enter text or URL…"
         maxLength={MAX_LENGTH}
-          rows={3}
-          className="resize-none font-mono text-sm"
+        rows={4}
+        className="w-full bg-transparent border border-border/40 rounded-lg px-3 py-2.5 text-xs font-mono outline-none focus:border-primary/50 transition-colors text-foreground/80 placeholder:text-muted-foreground/30 resize-none"
       />
-        <div className="text-[10px] text-muted-foreground text-right">
+      <div className="text-[9px] text-muted-foreground/30 font-mono text-right mt-1 tabular-nums">
         {value.length} / {MAX_LENGTH}
       </div>
-      </CardContent>
-    </Card>
+    </div>
   );
 }

components/qrcode/QROptions.tsx

@@ -1,17 +1,7 @@
 'use client';
 
-import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
-import { Label } from '@/components/ui/label';
-import { Input } from '@/components/ui/input';
-import { Button } from '@/components/ui/button';
 import { Slider } from '@/components/ui/slider';
-import {
-  Select,
-  SelectContent,
-  SelectItem,
-  SelectTrigger,
-  SelectValue,
-} from '@/components/ui/select';
+import { cn } from '@/lib/utils/cn';
 import type { ErrorCorrectionLevel } from '@/types/qrcode';
 
 interface QROptionsProps {
@@ -25,13 +15,16 @@ interface QROptionsProps {
   onMarginChange: (margin: number) => void;
 }
 
-const EC_OPTIONS: { value: ErrorCorrectionLevel; label: string }[] = [
-  { value: 'L', label: 'Low (7%)' },
-  { value: 'M', label: 'Medium (15%)' },
-  { value: 'Q', label: 'Quartile (25%)' },
-  { value: 'H', label: 'High (30%)' },
+const EC_OPTIONS: { value: ErrorCorrectionLevel; label: string; desc: string }[] = [
+  { value: 'L', label: 'L', desc: '7%' },
+  { value: 'M', label: 'M', desc: '15%' },
+  { value: 'Q', label: 'Q', desc: '25%' },
+  { value: 'H', label: 'H', desc: '30%' },
 ];
 
+const inputCls =
+  'w-full bg-transparent border border-border/40 rounded-lg px-3 py-1.5 text-xs font-mono outline-none focus:border-primary/50 transition-colors text-foreground/80 placeholder:text-muted-foreground/30';
+
 export function QROptions({
   errorCorrection,
   foregroundColor,
@@ -45,83 +38,102 @@ export function QROptions({
   const isTransparent = backgroundColor === '#00000000';
 
   return (
-    <Card>
-      <CardHeader>
-        <CardTitle>Options</CardTitle>
-      </CardHeader>
-      <CardContent className="space-y-4">
+    <div className="space-y-5">
+
       {/* Error Correction */}
-        <div className="space-y-1.5">
-          <Label className="text-xs">Error Correction</Label>
-          <Select value={errorCorrection} onValueChange={(v) => onErrorCorrectionChange(v as ErrorCorrectionLevel)}>
-            <SelectTrigger className="w-full">
-              <SelectValue />
-            </SelectTrigger>
-            <SelectContent>
+      <div>
+        <span className="text-[10px] font-semibold text-muted-foreground uppercase tracking-widest block mb-2">
+          Error Correction
+        </span>
+        <div className="flex gap-1.5">
           {EC_OPTIONS.map((opt) => (
-                <SelectItem key={opt.value} value={opt.value}>
-                  {opt.label}
-                </SelectItem>
+            <button
+              key={opt.value}
+              onClick={() => onErrorCorrectionChange(opt.value)}
+              className={cn(
+                'flex-1 flex flex-col items-center py-2 rounded-lg border text-xs font-mono transition-all',
+                errorCorrection === opt.value
+                  ? 'bg-primary/10 border-primary/40 text-primary'
+                  : 'border-border/30 text-muted-foreground hover:border-primary/30 hover:text-foreground'
+              )}
+            >
+              <span className="font-semibold">{opt.label}</span>
+              <span className="text-[9px] opacity-50 mt-0.5">{opt.desc}</span>
+            </button>
           ))}
-            </SelectContent>
-          </Select>
+        </div>
       </div>
 
       {/* Colors */}
       <div className="space-y-3">
-          <div className="space-y-1.5">
-            <Label className="text-xs">Foreground</Label>
-            <div className="flex gap-2">
-              <Input
+        <span className="text-[10px] font-semibold text-muted-foreground uppercase tracking-widest block">
+          Colors
+        </span>
+
+        {/* Foreground */}
+        <div>
+          <label className="text-[9px] text-muted-foreground/50 font-mono block mb-1.5">Foreground</label>
+          <div className="flex gap-1.5">
+            <input
               type="color"
-                className="w-9 p-1 h-9 shrink-0"
               value={foregroundColor}
               onChange={(e) => onForegroundColorChange(e.target.value)}
+              className="w-8 h-8 rounded-lg cursor-pointer border border-border/40 bg-transparent shrink-0 p-0.5"
             />
-              <Input
-                className="font-mono text-xs"
+            <input
+              type="text"
               value={foregroundColor}
               onChange={(e) => onForegroundColorChange(e.target.value)}
+              className={inputCls}
             />
           </div>
         </div>
-          <div className="space-y-1.5">
-            <div className="flex items-center justify-between">
-              <Label className="text-xs">Background</Label>
-              <Button
-                variant={isTransparent ? 'default' : 'outline'}
-                size="xs"
-                className="h-5 text-[10px] px-1.5"
-                onClick={() =>
-                  onBackgroundColorChange(isTransparent ? '#ffffff' : '#00000000')
-                }
+
+        {/* Background */}
+        <div>
+          <div className="flex items-center justify-between mb-1.5">
+            <label className="text-[9px] text-muted-foreground/50 font-mono">Background</label>
+            <button
+              onClick={() => onBackgroundColorChange(isTransparent ? '#ffffff' : '#00000000')}
+              className={cn(
+                'text-[9px] font-mono px-1.5 py-0.5 rounded border transition-all',
+                isTransparent
+                  ? 'border-primary/40 text-primary bg-primary/10'
+                  : 'border-border/30 text-muted-foreground/50 hover:border-primary/30 hover:text-primary'
+              )}
             >
               Transparent
-              </Button>
+            </button>
           </div>
-            <div className="flex gap-2">
-              <Input
+          <div className="flex gap-1.5">
+            <input
               type="color"
-                className="w-9 p-1 h-9 shrink-0"
               disabled={isTransparent}
-                value={backgroundColor}
+              value={isTransparent ? '#ffffff' : backgroundColor}
               onChange={(e) => onBackgroundColorChange(e.target.value)}
+              className={cn(
+                'w-8 h-8 rounded-lg cursor-pointer border border-border/40 bg-transparent shrink-0 p-0.5 transition-opacity',
+                isTransparent && 'opacity-30 cursor-not-allowed'
+              )}
             />
-              <Input
-                className="font-mono text-xs"
+            <input
+              type="text"
               disabled={isTransparent}
-                value={backgroundColor}
+              value={isTransparent ? 'transparent' : backgroundColor}
               onChange={(e) => onBackgroundColorChange(e.target.value)}
+              className={cn(inputCls, isTransparent && 'opacity-30')}
             />
           </div>
         </div>
       </div>
 
       {/* Margin */}
-        <div className="space-y-1.5">
-          <div className="flex items-center justify-between">
-            <Label className="text-xs">Margin</Label>
-            <span className="text-xs text-muted-foreground">{margin}</span>
+      <div>
+        <div className="flex items-center justify-between mb-2">
+          <span className="text-[10px] font-semibold text-muted-foreground uppercase tracking-widest">
+            Margin
+          </span>
+          <span className="text-[10px] text-muted-foreground/40 font-mono tabular-nums">{margin}</span>
         </div>
         <Slider
           value={[margin]}
@@ -131,7 +143,6 @@ export function QROptions({
           step={1}
         />
       </div>
-      </CardContent>
-    </Card>
+    </div>
   );
 }

components/qrcode/QRPreview.tsx

@@ -1,22 +1,7 @@
 'use client';
 
-import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
-import { Button } from '@/components/ui/button';
-import { Skeleton } from '@/components/ui/skeleton';
-import { ToggleGroup, ToggleGroupItem } from '@/components/ui/toggle-group';
-import {
-  Tooltip,
-  TooltipContent,
-  TooltipTrigger,
-} from '@/components/ui/tooltip';
-import {
-  Empty,
-  EmptyDescription,
-  EmptyHeader,
-  EmptyMedia,
-  EmptyTitle,
-} from '@/components/ui/empty';
 import { Copy, Share2, Image as ImageIcon, FileCode, QrCode } from 'lucide-react';
+import { cn } from '@/lib/utils/cn';
 import type { ExportSize } from '@/types/qrcode';
 
 interface QRPreviewProps {
@@ -30,6 +15,16 @@ interface QRPreviewProps {
   onDownloadSvg: () => void;
 }
 
+const EXPORT_SIZES: { value: ExportSize; label: string }[] = [
+  { value: 256, label: '256' },
+  { value: 512, label: '512' },
+  { value: 1024, label: '1k' },
+  { value: 2048, label: '2k' },
+];
+
+const actionBtn =
+  'flex items-center gap-1 px-2.5 py-1 text-xs glass rounded-md border border-border/30 text-muted-foreground hover:text-primary hover:border-primary/30 hover:bg-primary/10 transition-all disabled:opacity-40 disabled:cursor-not-allowed';
+
 export function QRPreview({
   svgString,
   isGenerating,
@@ -41,92 +36,81 @@ export function QRPreview({
   onDownloadSvg,
 }: QRPreviewProps) {
   return (
-    <Card className="h-full flex flex-col">
-      <CardHeader className="flex flex-row items-center justify-between flex-wrap gap-2">
-        <CardTitle>Preview</CardTitle>
-        <div className="flex items-center gap-1.5 flex-wrap">
-          <Tooltip>
-            <TooltipTrigger asChild>
-              <Button variant="outline" size="xs" onClick={onCopyImage} disabled={!svgString}>
-                <Copy className="h-3 w-3 mr-1" />
-                Copy
-              </Button>
-            </TooltipTrigger>
-            <TooltipContent>Copy image to clipboard</TooltipContent>
-          </Tooltip>
+    <div className="glass rounded-xl p-4 flex flex-col flex-1 min-h-0 overflow-hidden">
 
-          <Tooltip>
-            <TooltipTrigger asChild>
-              <Button variant="outline" size="xs" onClick={onShare} disabled={!svgString}>
-                <Share2 className="h-3 w-3 mr-1" />
-                Share
-              </Button>
-            </TooltipTrigger>
-            <TooltipContent>Copy shareable URL</TooltipContent>
-          </Tooltip>
+      {/* Action bar */}
+      <div className="flex items-center gap-1.5 mb-4 shrink-0 flex-wrap">
+        <span className="text-[10px] font-semibold text-muted-foreground uppercase tracking-widest mr-auto">
+          Preview
+        </span>
 
-          <div className="flex items-center gap-1">
-            <Tooltip>
-              <TooltipTrigger asChild>
-                <Button variant="outline" size="xs" onClick={onDownloadPng} disabled={!svgString}>
-                  <ImageIcon className="h-3 w-3 mr-1" />
-                  PNG
-                </Button>
-              </TooltipTrigger>
-              <TooltipContent>Download as PNG</TooltipContent>
-            </Tooltip>
-            <ToggleGroup
-              type="single"
-              value={String(exportSize)}
-              onValueChange={(v) => v && onExportSizeChange(Number(v) as ExportSize)}
-              variant="outline"
-              size="sm"
+        <button onClick={onCopyImage} disabled={!svgString} className={actionBtn}>
+          <Copy className="w-3 h-3" />Copy
+        </button>
+
+        <button onClick={onShare} disabled={!svgString} className={actionBtn}>
+          <Share2 className="w-3 h-3" />Share
+        </button>
+
+        {/* PNG + inline size selector */}
+        <div className="flex items-center glass rounded-md border border-border/30">
+          <button
+            onClick={onDownloadPng}
+            disabled={!svgString}
+            className="flex items-center gap-1 pl-2.5 pr-1.5 py-1 text-xs text-muted-foreground hover:text-primary transition-all disabled:opacity-40 disabled:cursor-not-allowed border-r border-border/20"
           >
-              <ToggleGroupItem value="256" className="h-6 px-1.5 min-w-0 text-[10px]">256</ToggleGroupItem>
-              <ToggleGroupItem value="512" className="h-6 px-1.5 min-w-0 text-[10px]">512</ToggleGroupItem>
-              <ToggleGroupItem value="1024" className="h-6 px-1.5 min-w-0 text-[10px]">1k</ToggleGroupItem>
-              <ToggleGroupItem value="2048" className="h-6 px-1.5 min-w-0 text-[10px]">2k</ToggleGroupItem>
-            </ToggleGroup>
+            <ImageIcon className="w-3 h-3" />PNG
+          </button>
+          <div className="flex items-center px-1 gap-0.5">
+            {EXPORT_SIZES.map(({ value, label }) => (
+              <button
+                key={value}
+                onClick={() => onExportSizeChange(value)}
+                className={cn(
+                  'text-[9px] font-mono px-1.5 py-0.5 rounded transition-all',
+                  exportSize === value
+                    ? 'text-primary bg-primary/10'
+                    : 'text-muted-foreground/40 hover:text-muted-foreground'
+                )}
+              >
+                {label}
+              </button>
+            ))}
+          </div>
         </div>
 
-          <Tooltip>
-            <TooltipTrigger asChild>
-              <Button variant="outline" size="xs" onClick={onDownloadSvg} disabled={!svgString}>
-                <FileCode className="h-3 w-3 mr-1" />
-                SVG
-              </Button>
-            </TooltipTrigger>
-            <TooltipContent>Download as SVG</TooltipContent>
-          </Tooltip>
+        <button onClick={onDownloadSvg} disabled={!svgString} className={actionBtn}>
+          <FileCode className="w-3 h-3" />SVG
+        </button>
       </div>
-      </CardHeader>
-      <CardContent className="flex-1 flex flex-col">
-        <div className="flex-1 min-h-[200px] rounded-lg p-4 flex items-center justify-center"
+
+      {/* QR canvas */}
+      <div
+        className="flex-1 min-h-0 rounded-xl flex items-center justify-center"
         style={{
-            backgroundImage: 'repeating-conic-gradient(hsl(var(--muted)) 0% 25%, transparent 0% 50%)',
+          backgroundImage: 'repeating-conic-gradient(rgba(255,255,255,0.025) 0% 25%, transparent 0% 50%)',
           backgroundSize: '16px 16px',
         }}
       >
         {isGenerating ? (
-            <Skeleton className="h-[200px] w-[200px]" />
+          <div className="w-56 h-56 rounded-xl bg-white/5 animate-pulse" />
         ) : svgString ? (
           <div
-              className="w-full max-w-[400px] aspect-square [&>svg]:w-full [&>svg]:h-full"
+            className="w-full max-w-sm aspect-square [&>svg]:w-full [&>svg]:h-full p-6"
             dangerouslySetInnerHTML={{ __html: svgString }}
           />
         ) : (
-            <Empty>
-              <EmptyHeader>
-                <EmptyMedia variant="icon">
-                  <QrCode />
-                </EmptyMedia>
-                <EmptyTitle>Enter text to generate a QR code</EmptyTitle>
-                <EmptyDescription>Type text or a URL in the input field above</EmptyDescription>
-              </EmptyHeader>
-            </Empty>
+          <div className="flex flex-col items-center gap-3 text-center">
+            <div className="w-14 h-14 rounded-full bg-primary/10 flex items-center justify-center">
+              <QrCode className="w-6 h-6 text-primary/40" />
+            </div>
+            <div>
+              <p className="text-sm font-medium text-foreground/40">No QR code yet</p>
+              <p className="text-[10px] text-muted-foreground/30 font-mono mt-1">Enter text or a URL to generate</p>
+            </div>
+          </div>
         )}
       </div>
-      </CardContent>
-    </Card>
+    </div>
   );
 }