fineui-start/src/modules/app/layout/layout.less

@import '~@/index.less';

.app-layout {
  .app-layout-header {
    .z-index-layer(2);
  }
  .app-layout-body {
    .z-index-layer(1);
    .app-layout-sider {
      .z-index-layer(2);
    }
    .app-layout-content {
      .z-index-layer(1);
    }
  }
}