diff --git a/jest.config.js b/jest.config.js
deleted file mode 100644
index 0c6601ae..00000000
--- a/jest.config.js
+++ /dev/null
@@ -1,4 +0,0 @@
-module.exports = {
-  setupFiles: ['./tests/setup.js'],
-  snapshotSerializers: [require.resolve('enzyme-to-json/serializer')],
-};
\ No newline at end of file
diff --git a/src/ScrollBar.tsx b/src/ScrollBar.tsx
index 832eadd1..c57ad969 100644
--- a/src/ScrollBar.tsx
+++ b/src/ScrollBar.tsx
@@ -45,7 +45,6 @@ const ScrollBar = React.forwardRef<ScrollBarRef, ScrollBarProps>((props, ref) =>
   const [dragging, setDragging] = React.useState(false);
   const [pageXY, setPageXY] = React.useState<number | null>(null);
   const [startTop, setStartTop] = React.useState<number | null>(null);
-  const [dark, setDark] = React.useState(false);
 
   const isLTR = !rtl;
 
@@ -188,21 +187,6 @@ const ScrollBar = React.forwardRef<ScrollBarRef, ScrollBarProps>((props, ref) =>
     }
   }, [dragging]);
 
-  React.useEffect(() => {
-    const media = window.matchMedia?.('(prefers-color-scheme: dark)');
-    setDark(media.matches);
-
-    const listener = (e: MediaQueryListEvent) => {
-      setDark(e.matches);
-    };
-
-    media?.addEventListener('change', listener);
-
-    return () => {
-      media?.removeEventListener('change', listener);
-    };
-  }, []);
-
   React.useEffect(() => {
     delayHidden();
     return () => {
@@ -225,45 +209,38 @@ const ScrollBar = React.forwardRef<ScrollBarRef, ScrollBarProps>((props, ref) =>
 
   const thumbStyle: React.CSSProperties = {
     position: 'absolute',
-    background: dark ? 'rgba(255, 255, 255, 0.5)' : 'rgba(0, 0, 0, 0.5)',
     borderRadius: 99,
+    background: 'var(--rc-virtual-list-scrollbar-bg, rgba(0, 0, 0, 0.5))',
     cursor: 'pointer',
     userSelect: 'none',
-    ...propsThumbStyle,
   };
 
   if (horizontal) {
-    // Container
-    containerStyle.height = 8;
-    containerStyle.left = 0;
-    containerStyle.right = 0;
-    containerStyle.bottom = 0;
-
-    // Thumb
-    thumbStyle.height = '100%';
-    thumbStyle.width = spinSize;
-
-    if (isLTR) {
-      thumbStyle.left = top;
-    } else {
-      thumbStyle.right = top;
-    }
+    Object.assign(containerStyle, {
+      height: 8,
+      left: 0,
+      right: 0,
+      bottom: 0,
+    });
+  
+    Object.assign(thumbStyle, {
+      height: '100%',
+      width: spinSize,
+      [isLTR ? 'left' : 'right']: top,
+    });
   } else {
-    // Container
-    containerStyle.width = 8;
-    containerStyle.top = 0;
-    containerStyle.bottom = 0;
-
-    if (isLTR) {
-      containerStyle.right = 0;
-    } else {
-      containerStyle.left = 0;
-    }
-
-    // Thumb
-    thumbStyle.width = '100%';
-    thumbStyle.height = spinSize;
-    thumbStyle.top = top;
+    Object.assign(containerStyle, {
+      width: 8,
+      top: 0,
+      bottom: 0,
+      [isLTR ? 'right' : 'left']: 0,
+    });
+  
+    Object.assign(thumbStyle, {
+      width: '100%',
+      height: spinSize,
+      top,
+    });
   }
 
   return (
@@ -283,7 +260,7 @@ const ScrollBar = React.forwardRef<ScrollBarRef, ScrollBarProps>((props, ref) =>
         className={classNames(`${scrollbarPrefixCls}-thumb`, {
           [`${scrollbarPrefixCls}-thumb-moving`]: dragging,
         })}
-        style={{ ...thumbStyle }}
+        style={{ ...thumbStyle, ...propsThumbStyle }}
         onMouseDown={onThumbMouseDown}
       />
     </div>
diff --git a/tests/dark.test.js b/tests/dark.test.js
deleted file mode 100644
index 6e8454ae..00000000
--- a/tests/dark.test.js
+++ /dev/null
@@ -1,101 +0,0 @@
-import React from 'react';
-import { mount } from 'enzyme';
-import { act } from 'react-dom/test-utils';
-import List from '../src';
-
-describe('List.dark', () => {
-  const originalMatchMedia = window.matchMedia;
-
-  afterEach(() => {
-    window.matchMedia = originalMatchMedia;
-  });
-
-  const mockMatchMedia = (matches) => {
-    Object.defineProperty(window, 'matchMedia', {
-      writable: true,
-      value: jest.fn().mockImplementation(query => ({
-        matches,
-        media: query,
-        onchange: null,
-        addListener: jest.fn(), // deprecated
-        removeListener: jest.fn(), // deprecated
-        addEventListener: jest.fn(),
-        removeEventListener: jest.fn(),
-        dispatchEvent: jest.fn(),
-      })),
-    });
-  };
-
-  it('should render dark scrollbar', () => {
-    mockMatchMedia(true);
-
-    const wrapper = mount(
-      <List data={[1, 2, 3]} height={10} itemHeight={5} itemKey={(item) => item}>
-        {(item) => <div>{item}</div>}
-      </List>
-    );
-
-    const thumb = wrapper.find('.rc-virtual-list-scrollbar-thumb');
-    expect(thumb.props().style.background).toBe('rgba(255, 255, 255, 0.5)');
-  });
-
-  it('should render light scrollbar', () => {
-    mockMatchMedia(false);
-
-    const wrapper = mount(
-      <List data={[1, 2, 3]} height={10} itemHeight={5} itemKey={(item) => item}>
-        {(item) => <div>{item}</div>}
-      </List>
-    );
-
-    const thumb = wrapper.find('.rc-virtual-list-scrollbar-thumb');
-    expect(thumb.props().style.background).toBe('rgba(0, 0, 0, 0.5)');
-  });
-
-  it('should update on theme change', () => {
-    let listener;
-    Object.defineProperty(window, 'matchMedia', {
-      writable: true,
-      value: jest.fn().mockImplementation(() => ({
-        matches: false,
-        addEventListener: (type, cb) => {
-          if (type === 'change') {
-            listener = cb;
-          }
-        },
-        removeEventListener: () => {},
-      })),
-    });
-
-    const wrapper = mount(
-      <List data={[1, 2, 3]} height={10} itemHeight={5} itemKey={(item) => item}>
-        {(item) => <div>{item}</div>}
-      </List>
-    );
-
-    // Initial: light
-    expect(wrapper.find('.rc-virtual-list-scrollbar-thumb').props().style.background).toBe(
-      'rgba(0, 0, 0, 0.5)',
-    );
-
-    // Change to dark
-    act(() => {
-      listener({ matches: true });
-    });
-    wrapper.update();
-
-    expect(wrapper.find('.rc-virtual-list-scrollbar-thumb').props().style.background).toBe(
-      'rgba(255, 255, 255, 0.5)',
-    );
-
-    // Change back to light
-    act(() => {
-      listener({ matches: false });
-    });
-    wrapper.update();
-
-    expect(wrapper.find('.rc-virtual-list-scrollbar-thumb').props().style.background).toBe(
-      'rgba(0, 0, 0, 0.5)',
-    );
-  });
-}); 
\ No newline at end of file
diff --git a/tests/setup.js b/tests/setup.js
deleted file mode 100644
index 87237082..00000000
--- a/tests/setup.js
+++ /dev/null
@@ -1,13 +0,0 @@
-Object.defineProperty(window, 'matchMedia', {
-  writable: true,
-  value: jest.fn().mockImplementation(query => ({
-    matches: false,
-    media: query,
-    onchange: null,
-    addListener: jest.fn(), // deprecated
-    removeListener: jest.fn(), // deprecated
-    addEventListener: jest.fn(),
-    removeEventListener: jest.fn(),
-    dispatchEvent: jest.fn(),
-  })),
-});
\ No newline at end of file