feat: redesign admin layout and stats dashboards

app-frontend/src/pages/LoginPage.vue

@@ -308,11 +308,6 @@ onMounted(async () => {
         <span>还没有账号？</span>
         <button type="button" class="link-btn" @click="goRegister">立即注册</button>
       </div>
-
-      <div class="back-link">
-        <span>管理员请前往</span>
-        <a href="/yuyx">后台登录</a>
-      </div>
     </div>
 
     <el-dialog v-model="forgotOpen" title="找回密码" width="min(560px, 92vw)">
@@ -549,23 +544,6 @@ onMounted(async () => {
   font-size: 13px;
 }
 
-.back-link {
-  text-align: center;
-  margin-top: 18px;
-  color: #6b7280;
-  font-size: 13px;
-}
-
-.back-link a {
-  margin-left: 6px;
-  color: #2563eb;
-  text-decoration: none;
-  font-weight: 700;
-}
-
-.back-link a:hover {
-  text-decoration: underline;
-}
 
 .dialog-form {
   margin-top: 10px;