:root {::-webkit-scrollbar {width: 7px;height: 5px;background: #fff;border-radius: 5px; /*外层轨道*/}::-webkit-scrollbar-thumb {display: block;width: 2px;margin: 0 auto;border-radius: 5px;background: #ccc; /*内层轨道*/transition: all .2s ease-in-out;}
}

设置前

设置后