情绪大模型返回顶部全局唯一；情绪大模型手机端加入背景颜色；

src/views/AiEmotion.vue

@@ -213,15 +213,16 @@
           </div>
         </div>
 
-        <!-- 返回顶部按钮 -->
-        <div class="back-to-top" @click="scrollToTop" v-show="isPageLoaded">
-          <svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
-            <path d="M12 4L12 20M12 4L6 10M12 4L18 10" stroke="currentColor" stroke-width="2" stroke-linecap="round"
-              stroke-linejoin="round" />
-          </svg>
-        </div>
       </div>
     </div>
+    
+    <!-- 全局返回顶部按钮 -->
+    <div class="back-to-top" @click="scrollToTop" v-if="(filteredStockList.length > 0 || messages.length > 0)">
+      <svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
+        <path d="M12 4L12 20M12 4L6 10M12 4L18 10" stroke="currentColor" stroke-width="2" stroke-linecap="round"
+          stroke-linejoin="round" />
+      </svg>
+    </div>
   </div>
 </template>
 
@@ -3998,9 +3999,11 @@ const emit = defineEmits(['updateMessage', 'sendMessage', 'ensureAIchat']);
   }
 
   .main {
-    width: 100%;
+    width: 90%;
     padding: 0.5rem;
     margin-bottom: 5rem;
+    background-color: #2b378d;
+    border-radius: 0px 0px 10px 10px;
   }
 
   .energy-converter-text {