fix(components-react): picker 全屏蒙层主题命中与可配置颜色

overlay 增加 theme 修饰类并修正 SCSS 选择器，使 light/dark 蒙层色生效；移除主题块内无效的 mask-overlay 嵌套；colors 新增 maskColor 覆盖蒙层背景。

Author: Muyouz

packages/taro-components-react/src/components/picker/index.tsx

@@ -114,6 +114,8 @@ export interface PickerColors {
   backgroundColor?: string // 面板背景色
   lineColor?: string // 指示线条颜色
   titleColor?: string // 标题颜色
+  /** 全屏点击蒙层背景色；不设则随 theme 使用默认浅色/深色蒙层 */
+  maskColor?: string
 }
 
 export interface PickerDate {
@@ -921,6 +923,7 @@ const Picker = React.forwardRef<PickerRef, IProps>((props, ref) => {
   })
   const backgroundStyle = colors.backgroundColor ? { backgroundColor: colors.backgroundColor } : null
   const titleStyle = colors.titleColor ? { color: colors.titleColor } : null
+  const maskOverlayStyle = colors.maskColor ? { backgroundColor: colors.maskColor } : undefined
 
   // 暴露方法给外部
   React.useImperativeHandle(ref, () => ({
@@ -941,8 +944,8 @@ const Picker = React.forwardRef<PickerRef, IProps>((props, ref) => {
         {children}
       </View>
       {!state.hidden && (
-        <View className="taro-picker__overlay">
-          <View className={clsMask} onClick={handleCancel} />
+        <View className={classNames('taro-picker__overlay', `taro-picker__overlay--theme-${theme}`)}>
+          <View className={clsMask} style={maskOverlayStyle} onClick={handleCancel} />
           <View className={clsSlider} {...(backgroundStyle ? { style: backgroundStyle } : {})}>
             <View className="taro-picker__hd" {...(backgroundStyle ? { style: backgroundStyle } : {})}>
               <View

packages/taro-components-react/src/components/picker/style/index.scss

@@ -24,6 +24,15 @@
   z-index: $weuiPickerZIndexMask;
 }
 
+// 全屏蒙层颜色：mask 与 taro-picker-theme-* 面板为兄弟节点，由 overlay 主题修饰类命中
+.taro-picker__overlay.taro-picker__overlay--theme-light .taro-picker__mask-overlay {
+  background-color: $weuiMaskColorLight;
+}
+
+.taro-picker__overlay.taro-picker__overlay--theme-dark .taro-picker__mask-overlay {
+  background-color: $weuiMaskColorDark;
+}
+
 .taro-picker {
   position: absolute;
   bottom: 0;
@@ -88,10 +97,6 @@
 .taro-picker-theme-light {
   background-color: $weuiLineColorLight;
 
-  .taro-picker__mask-overlay {
-    background-color: $weuiMaskColorLight;
-  }
-
   .taro-picker__hd {
     background-color: $weuiBackgroundColorLight;
 
@@ -151,10 +156,6 @@
 .taro-picker-theme-dark {
   background-color: $weuiLineColorDark;
 
-  .taro-picker__mask-overlay {
-    background-color: $weuiMaskColorDark;
-  }
-
   .taro-picker__hd {
     background-color: $weuiBackgroundColorDark;