整理router，删除多余中单件和路由。退出按键放最上方。

static/css/adminstyle.css

@@ -22,20 +22,27 @@ body {
     display: flex;
     flex-direction: column;
 }
-
-.logo {
-    padding: 20px;
-    border-bottom: 1px solid rgba(255,255,255,0.1);
+.admin-header {
+    padding: 15px 20px;
+    display: flex;
+    justify-content: space-between;
+    background-color: #001529;
+    color: #fff;
+    align-items: center;
+}
+.admin-header #username {
+    margin-left: auto;
+}
+.admin-header span {
+    background: transparent;
+    padding: 5px 12px;
+    border-radius: 4px;
+    color: #fff;
+    cursor: pointer;
 }
 
-.logo h2 {
-    font-size: 20px;
-}
-
-.logo p {
-    font-size: 12px;
-    color: rgba(255,255,255,0.6);
-    margin-top: 5px;
+.admin-header span:hover {
+    background: rgba(255,255,255,0.1);
 }
 
 .menu {
@@ -97,27 +104,6 @@ body {
     background: #1890ff;
 }
 
-.user-info {
-    padding: 15px 20px;
-    border-top: 1px solid rgba(255,255,255,0.1);
-    display: flex;
-    justify-content: space-between;
-    align-items: center;
-}
-
-.user-info button {
-    background: transparent;
-    border: 1px solid rgba(255,255,255,0.3);
-    color: #fff;
-    padding: 5px 12px;
-    border-radius: 4px;
-    cursor: pointer;
-}
-
-.user-info button:hover {
-    background: rgba(255,255,255,0.1);
-}
-
 /* 主内容区 */
 .main-content {
     flex: 1;