无选项样式优化

scss/_mixins.scss

@@ -382,3 +382,12 @@
     }
   }
 }
+
+@mixin checkboxes-placeholder {
+  height: $Form-input-height;
+  line-height: $Form-input-lineHeight;
+  font-size: $Form-input-fontSize;
+  padding: ($Form-input-height - $Form-input-lineHeight * $Form-input-fontSize)/2
+    $gap-sm;
+  color: $text--muted-color;
+}

scss/components/form/_checks.scss

@@ -279,15 +279,6 @@
   display: block;
 }
 
-@mixin checkboxes-placeholder {
-  height: $Form-input-height;
-  line-height: $Form-input-lineHeight;
-  font-size: $Form-input-fontSize;
-  padding: ($Form-input-height - $Form-input-lineHeight * $Form-input-fontSize)/2
-    $gap-sm;
-  color: $text--muted-color;
-}
-
 .#{$ns}Checkboxes {
   > .#{$ns}Checkbox {
     display: block;

scss/components/form/_transfer.scss

@@ -164,6 +164,10 @@
   // .#{$ns}Transfer-result {
   //   flex-grow: unset;
   // }
+
+  &-placeholder {
+    @include checkboxes-placeholder();
+  }
 }
 
 .#{$ns}TransferControl {

src/components/TabsTransfer.tsx

@@ -89,7 +89,11 @@ export class TabsTransfer extends React.Component<TabsTransferProps> {
     } = this.props;
 
     if (!Array.isArray(options) || !options.length) {
-      return <div>{placeholder || '暂无可选项'}</div>;
+      return (
+        <div className={cx('TabsTransfer-placeholder')}>
+          {placeholder || '暂无可选项'}
+        </div>
+      );
     }
 
     return (