- 在 index.html:47-51 给 main 和左侧面板增加 min-h-0，允许网格子项在父级 flex 容器中释放高度，确保

#chat-history 的 overflow-y-auto 生效；右侧展示区同样设置 min-h-0，防止 SVG 区域被异常拉伸。
  - 调整后，长对话会保持面板固定高度，滚动条承载多余内容，不再把整个页面撑出视窗。

css/style.css

@@ -2,6 +2,15 @@ body {
   font-family: 'Inter', sans-serif;
 }
 
+/* 统一处理 Iconify 图标的对齐方式，避免在按钮与文字中出现垂直偏移 */
+iconify-icon {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  vertical-align: middle;
+  line-height: 1;
+}
+
 /* 狂野线条效果 */
 .wild-border {
   border: 3px solid;
@@ -223,9 +232,22 @@ body {
   transition: color 0.2s ease;
 }
 
+.svg-placeholder-block {
+  position: relative;
+}
+
+@keyframes svg-active-pulse {
+  0% { box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.35), 0 6px 12px rgba(15, 23, 42, 0.15); }
+  50% { box-shadow: 0 0 0 6px rgba(37, 99, 235, 0.15), 0 10px 18px rgba(15, 23, 42, 0.2); }
+  100% { box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.35), 0 6px 12px rgba(15, 23, 42, 0.15); }
+}
+
 .svg-placeholder-active {
-  border-color: #2563eb;
+  border-color: #1d4ed8;
-  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
+  background: linear-gradient(135deg, #e0f2fe 0%, #dbeafe 100%);
+  color: #1e3a8a;
+  transform: translateY(-2px);
+  /* animation: svg-active-pulse 1.6s ease-in-out infinite; */
 }
 
 .svg-content-wrapper {

index.html

@@ -25,6 +25,7 @@
       <div class="flex items-center gap-3">
         <!-- API配置按钮 -->
         <button id="settings-btn" class="settings-btn bg-white/20 text-white p-2 border-2 border-white hover:bg-white/30 transition-all" title="API配置">
+          API配置
           <iconify-icon icon="ph:gear-six-fill" class="text-2xl"></iconify-icon>
         </button>
         
@@ -43,10 +44,10 @@
     </header>
 
     <!-- 主内容区 -->
-    <main class="flex-1 grid grid-cols-1 md:grid-cols-3 gap-4 p-4 overflow-hidden">
+    <main class="flex-1 min-h-0 grid grid-cols-1 md:grid-cols-3 gap-4 p-4 overflow-hidden">
     
       <!-- 左侧对话面板 -->
-      <div class="md:col-span-1 bg-white wild-border border-cyan-500 flex flex-col">
+      <div class="md:col-span-1 bg-white wild-border border-cyan-500 flex flex-col min-h-0">
         <!-- 对话历史顶部栏 -->
         <div class="p-3 border-b-3 border-gray-300 bg-gradient-to-r from-cyan-500 to-blue-500 flex items-center justify-between">
           <div class="flex items-center gap-2">
@@ -85,7 +86,7 @@
       </div>
     
       <!-- 右侧显示面板 -->
-      <div class="md:col-span-2 bg-white wild-border border-purple-600 flex flex-col">
+      <div class="md:col-span-2 bg-white wild-border border-purple-600 flex flex-col min-h-0">
         <div id="svg-viewer" class="flex-1 flex items-center justify-center p-4 bg-gradient-to-br from-purple-50 to-pink-50 overflow-auto">
           <div id="svg-placeholder" class="text-center text-gray-400">
             <iconify-icon icon="ph:image-square" class="text-6xl mx-auto text-purple-400"></iconify-icon>

js/app.js

@@ -26,6 +26,8 @@ class ProductCanvasApp {
     this.pendingSvgId = null;
     this.pendingCancel = false;
     this.copyClipboardSupported = typeof ClipboardItem !== 'undefined' && !!navigator.clipboard;
+    const deviceScale = typeof window !== 'undefined' ? (window.devicePixelRatio || 1) : 1;
+    this.imageExportScale = Math.min(4, Math.max(2, deviceScale));
     
     this.initElements();
     this.initEventListeners();
@@ -1214,7 +1216,7 @@ class ProductCanvasApp {
     });
   }
 
-  async convertSvgToPngBlob(svgContent) {
+  async convertSvgToPngBlob(svgContent, options = {}) {
     const { width, height } = this.parseSvgDimensions(svgContent);
     const svgBlob = new Blob([svgContent], { type: 'image/svg+xml' });
     const url = URL.createObjectURL(svgBlob);
@@ -1222,14 +1224,16 @@ class ProductCanvasApp {
     try {
       const img = await this.loadImageFromUrl(url);
       const canvas = document.createElement('canvas');
-      const canvasWidth = Math.max(1, img.naturalWidth || width || 1024);
+      const baseWidth = Math.max(1, img.naturalWidth || width || 1024);
-      const canvasHeight = Math.max(1, img.naturalHeight || height || 768);
+      const baseHeight = Math.max(1, img.naturalHeight || height || 768);
-      canvas.width = canvasWidth;
+      const preferredScale = options.scale || this.imageExportScale || 1;
-      canvas.height = canvasHeight;
+      const exportScale = Math.min(4, Math.max(1, preferredScale));
+      canvas.width = Math.round(baseWidth * exportScale);
+      canvas.height = Math.round(baseHeight * exportScale);
 
       const ctx = canvas.getContext('2d');
-      ctx.clearRect(0, 0, canvasWidth, canvasHeight);
+      ctx.clearRect(0, 0, canvas.width, canvas.height);
-      ctx.drawImage(img, 0, 0, canvasWidth, canvasHeight);
+      ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
 
       return await new Promise((resolve, reject) => {
         canvas.toBlob((blob) => {