body {
    overflow-y: auto;
}
/*滚动条样式*/
body::-webkit-scrollbar { /*滚动条整体样式*/
    width: 4px; /*高宽分别对应横竖滚动条的尺寸*/
    height: 4px;
}

body::-webkit-scrollbar-thumb { /*滚动条里面小方块*/
    border-radius: 5px;
    -webkit-box-shadow: inset 0 0 5px rgba(0,0,0,0.2);
    background: rgba(0,0,0,0.2);
}

body::-webkit-scrollbar-track { /*滚动条里面轨道*/
    -webkit-box-shadow: inset 0 0 5px rgba(0,0,0,0.2);
    border-radius: 0;
    background: rgba(0,0,0,0.1);
}