W3School TIY Editor

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
/* 宽度 */
::-webkit-scrollbar {
 width: 10px;
}

/* 滚动条轨道 */
::-webkit-scrollbar-track {
  background: #f1f1f1; 
}
 
/* 滚动条滑块 */
::-webkit-scrollbar-thumb {
  background: #888; 
}

/* 悬停时的滑块 */
::-webkit-scrollbar-thumb:hover {
 background: #555; 
}
</style>
</head>

<body>
<h1>自定义滚动条</h1>

注意：在 Firefox 或 Edge 79 之前的版本中不支持 -webkit-scrollbar。

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</body>
</html>