fix(table): wrong bg-color in fullscreen mode

修复浅色主题下的table在全屏状态时背景颜色不正确的问题

src/design/theme.less

@@ -21,6 +21,10 @@ html[data-theme='light'] {
     background-color: #fffbe6;
     border: 1px solid #ffe58f;
   }
+
+  :not(:root):fullscreen::backdrop {
+    background-color: @layout-body-background !important;
+  }
 }
 
 [data-theme='dark'] {