fix: 统一导航栏所有 72px → 56px

- nav-item 高度
- nav-cont top
- login-in 高度
- login-menu top
- css/common.css nav-header 高度

common/common.css

@@ -119,7 +119,7 @@ body {
   color: rgba(220, 228, 240, 0.9);
   display: flex;
   align-items: center;
-  height: 72px;
+  height: 56px;
   padding: 0 20px;
   font-size: 15px;
   cursor: pointer;
@@ -215,7 +215,7 @@ body {
 /* 菜单栏 - 背景由 nav-mega-menu.css 统一管理 */
 .nav-cont {
   position: absolute;
-  top: 72px;
+  top: 56px;
   width: 100%;
   overflow: hidden;
   background: transparent;
@@ -288,7 +288,7 @@ body {
 .nav-header .login-in {
   cursor: pointer;
   position: relative;
-  height: 72px;
+  height: 56px;
   display: flex;
   align-items: center;
   z-index: 999;
@@ -333,7 +333,7 @@ body {
   display: none;
   padding: 6px;
   position: absolute;
-  top: 72px;
+  top: 56px;
   left: 0;
   width: 168px;
   background: rgba(14, 16, 26, 0.98);