Update app.py

app.py

@@ -308,21 +308,26 @@ def render_img(b64_list, idx, scale):
         #     f'</div>'
         # )
 
-        return f'''
+        return f"""
             <div style="
-                overflow:auto;border:1px solid #ccc;
-                display:flex;
-                justify-content:center;
-                align-items:center;   /* 垂直也居中 */
-                width:100%;height:800px;">
-                <img src="{src}"
-                     style="
-                       width:{percent}%;
-                       max-width:none;
-                       height:auto;
-                       flex-shrink:0;" />
+                width:100%;
+                height:800px;
+                overflow:auto;
+                border:1px solid #ccc;
+            ">
+              <div style="
+                  min-width:100%;           /* 保证外层 div 至少跟容器一样宽 */
+                  display:flex;
+                  justify-content:center;   /* 小图水平居中 */
+              ">
+                <img src="{src}" style="
+                    width:{percent}%;
+                    height:auto;
+                    display:block;
+                ">
+              </div>
             </div>
-            '''
+            """
     else:
         # ---------- 放大模式 ----------
         return (