style(common.css): 更新导航项样式以增强布局一致性

public/themes/dist_static/static/css/common.css

@@ -1094,9 +1094,12 @@ body {
   margin: 0;
   padding: 0;
   list-style: none;
-}.site-header__nav > ul li {
+}
+.site-header__nav .site-header__nav-item{
   padding-left: 1rem;
   padding-right: 1rem;
+}
+.site-header__nav > ul li {
   height: 100%;
 }.site-header__nav > ul > li > a {
   display: inline-flex;