fix #4079 PageHeaderWrapper margin in xs screen (#4081)

* fix PageHeaderWrapper margin in xs screen, #4079

* fix: PageHeaderWrapper doesn't perform as expected on xs screen

src/components/PageHeaderWrapper/index.less

@@ -43,7 +43,7 @@
   }
 
   @media screen and (max-width: @screen-sm) {
-    .content {
+    .children-content {
       margin: 24px 0 0;
     }
   }
@@ -77,21 +77,20 @@
     margin-left: 88px;
     text-align: right;
   }
-}
 
-@media screen and (max-width: @screen-xl) {
+  @media screen and (max-width: @screen-xl) {
     .extraContent {
       margin-left: 44px;
     }
-}
+  }
 
-@media screen and (max-width: @screen-lg) {
+  @media screen and (max-width: @screen-lg) {
     .extraContent {
       margin-left: 20px;
     }
-}
+  }
 
-@media screen and (max-width: @screen-md) {
+  @media screen and (max-width: @screen-md) {
     .row {
       display: block;
     }
@@ -101,10 +100,11 @@
       margin-left: 0;
       text-align: left;
     }
-}
+  }
 
-@media screen and (max-width: @screen-sm) {
+  @media screen and (max-width: @screen-sm) {
     .detail {
       display: block;
     }
+  }
 }