修复GlobalHeader中RightContent样式问题 (#5171)

* 修复GlobalHeader中RightContent样式问题

修改GlobalHeader中RightContent在dark模式下, @media only screen and (max-width: @screen-md) 注:(768px)的样式错误

* 修复dark&topmenu模式下GlobalHeader中图标颜色问题

修复dark&topmenu模式下GlobalHeader中图标颜色问题

src/components/GlobalHeader/index.less

@@ -91,6 +91,23 @@
   }
 }
 
+:global(.ant-pro-global-header) {
+  .dark {
+    .action {
+      color: @text-color;
+      > i {
+        color: @text-color;
+      }
+      &:hover {
+        color: rgba(255, 255, 255, 0.85);
+        > i {
+          color: rgba(255, 255, 255, 0.85);
+        }
+      }
+    }
+  }
+}
+
 @media only screen and (max-width: @screen-md) {
   :global(.ant-divider-vertical) {
     vertical-align: unset;
@@ -110,7 +127,6 @@
     position: absolute;
     top: 0;
     right: 12px;
-    background: #fff;
     .account {
       .avatar {
         margin-right: 0;