修复.user-name不生效问题(make the .user-name style in Header.vue work)

src/components/Header.vue

@@ -22,7 +22,8 @@
                     <img src="../assets/img/img.jpg" />
                 </div>
                 <!-- 用户名下拉菜单 -->
-                <el-dropdown class="user-name" trigger="click" @command="handleCommand">
+               <div class="user-name">
+                 <el-dropdown trigger="click" @command="handleCommand">
                     <span class="el-dropdown-link">
                         {{username}}
                         <i class="el-icon-caret-bottom"></i>
@@ -40,6 +41,7 @@
                </div>
             </div>
         </div>
+    </div>
 </template>
 <script>
 import { computed, onMounted } from "vue";