fix: dropdown down icon size (#41501)

components/dropdown/style/button.ts

@@ -1,26 +0,0 @@
-import type { DropdownToken } from '.';
-import type { GenerateStyle } from '../../theme/internal';
-
-const genButtonStyle: GenerateStyle<DropdownToken> = (token) => {
-  const { componentCls, antCls, paddingXS, opacityLoading } = token;
-
-  return {
-    [`${componentCls}-button`]: {
-      whiteSpace: 'nowrap',
-
-      [`&${antCls}-btn-group > ${antCls}-btn`]: {
-        [`&-loading, &-loading + ${antCls}-btn`]: {
-          cursor: 'default',
-          pointerEvents: 'none',
-          opacity: opacityLoading,
-        },
-
-        [`&:last-child:not(:first-child):not(${antCls}-btn-icon-only)`]: {
-          paddingInline: paddingXS,
-        },
-      },
-    },
-  };
-};
-
-export default genButtonStyle;

components/dropdown/style/index.ts

@@ -11,7 +11,6 @@ import {
 import getArrowStyle, { getArrowOffset } from '../../style/placementArrow';
 import type { FullToken, GenerateStyle } from '../../theme/internal';
 import { genComponentStyleHook, mergeToken } from '../../theme/internal';
-import genButtonStyle from './button';
 import genStatusStyle from './status';
 
 export interface ComponentToken {
@@ -71,6 +70,11 @@ const genBaseStyle: GenerateStyle<DropdownToken> = (token) => {
           content: '""',
         },
 
+        [`&-trigger${antCls}-btn > ${iconCls}-down`]: {
+          fontSize: fontSizeIcon,
+          transform: 'none',
+        },
+
         [`${componentCls}-wrap`]: {
           position: 'relative',
 
@@ -350,11 +354,7 @@ export default genComponentStyleHook(
       dropdownPaddingVertical,
       dropdownEdgeChildPadding: paddingXXS,
     });
-    return [
-      genBaseStyle(dropdownToken),
-      genButtonStyle(dropdownToken),
-      genStatusStyle(dropdownToken),
-    ];
+    return [genBaseStyle(dropdownToken), genStatusStyle(dropdownToken)];
   },
   (token) => ({
     zIndexPopup: token.zIndexPopupBase + 50,