优化悬浮球：使用微信群图标，保持二维码图片原有比例

Author: CC11001100

src/components/WechatGroupFloat.tsx

@@ -10,7 +10,10 @@ const WechatGroupFloat: React.FC = () => {
       onMouseLeave={() => setShowQR(false)}
     >
       <div className="float-btn">
-        <span>💬</span>
+        <svg viewBox="0 0 24 24" width="24" height="24" fill="white">
+          <path d="M8.5 3C4.36 3 1 5.69 1 9c0 1.78 1.02 3.37 2.6 4.45l-.6 2.35 2.7-1.35c.87.25 1.8.4 2.8.4.33 0 .66-.02.98-.05C9.17 13.97 9 13.01 9 12c0-3.87 3.58-7 8-7 .34 0 .67.02 1 .05C17.13 3.2 13.16 1.5 8.5 3zM6 8a1 1 0 110-2 1 1 0 010 2zm5 0a1 1 0 110-2 1 1 0 010 2z"/>
+          <path d="M23 14c0-2.76-2.69-5-6-5s-6 2.24-6 5 2.69 5 6 5c.7 0 1.37-.1 2-.28l2.2 1.1-.5-1.9C22.22 16.77 23 15.45 23 14zm-8-1a1 1 0 110-2 1 1 0 010 2zm4 0a1 1 0 110-2 1 1 0 010 2z"/>
+        </svg>
         <span className="float-text">交流群</span>
       </div>
 

src/index.css

@@ -2128,8 +2128,8 @@ select:focus {
 }
 
 .qr-popup img {
-  width: 180px;
-  height: 180px;
+  max-width: 200px;
+  height: auto;
   border-radius: 8px;
 }