调整部分前端布局和后端增删改逻辑

shierfeng-fastapi-frontend/src/layout/components/Navbar.vue

@@ -156,7 +156,8 @@ async function toggleTheme(event) {
   overflow: hidden;
   position: relative;
   background: var(--navbar-bg);
-  box-shadow: 0 1px 4px rgba(0, 21, 41, 0.08);
+  border-bottom: 1px solid var(--el-border-color-lighter, #e4e7ed);
+  box-shadow: 0 1px 4px rgba(15, 34, 58, 0.04);
   display: flex;
   align-items: center;
   // padding: 0 8px;
@@ -216,19 +217,22 @@ async function toggleTheme(event) {
     }
 
     .right-menu-item {
-      display: inline-block;
+      display: inline-flex;
+      align-items: center;
+      justify-content: center;
       padding: 0 8px;
       height: 100%;
       font-size: 18px;
-      color: #5a5e66;
-      vertical-align: text-bottom;
+      color: var(--el-text-color-regular, #5a5e66);
+      vertical-align: middle;
 
       &.hover-effect {
         cursor: pointer;
-        transition: background 0.3s;
+        transition: background 0.3s, color 0.2s;
 
         &:hover {
-          background: rgba(0, 0, 0, 0.025);
+          background: rgba(0, 0, 0, 0.035);
+          color: var(--el-color-primary, #008596);
         }
       }
 
@@ -247,30 +251,36 @@ async function toggleTheme(event) {
     }
 
     .avatar-container {
-      margin-right: 0px;
-      padding-right: 0px;
+      margin-right: 4px;
+      padding: 0 4px;
 
       .avatar-wrapper {
-        margin-top: 10px;
-        right: 8px;
         position: relative;
+        display: flex;
+        align-items: center;
+        gap: 8px;
+        padding: 4px 8px;
+        border-radius: 20px;
+        transition: background 0.25s ease;
+
+        &:hover {
+          background: rgba(0, 0, 0, 0.04);
+        }
 
         .user-avatar {
           cursor: pointer;
-          width: 30px;
-          height: 30px;
-          margin-right: 8px;
+          width: 32px;
+          height: 32px;
           border-radius: 50%;
-          vertical-align: middle;
-          border-style: none;
+          object-fit: cover;
+          border: 1.5px solid var(--el-color-primary-light-7, #b2e0e6);
+          box-shadow: 0 2px 6px rgba(0, 133, 150, 0.12);
         }
 
-        .user-nickname{
-          position: relative;
-          left: 0px;
-          // bottom: 10px;
-          font-size: 14px;
-          font-weight: bold;
+        .user-nickname {
+          font-size: 13px;
+          font-weight: 500;
+          color: var(--el-text-color-primary, #303133);
         }
 
         i {