css修改滚动条默认样式

• html代码

<div class="inner">
    <div class="innerbox">
        <p style="height:200px;">这是内容111</p>
        <p style="height:400px;">这里是内容222</p>
        <p>这里是内容333</p>
    </div>
</div>

• css代码

.inner{
    width: 265px;
    height: 400px;
    position: absolute;
    top: 33px;
    left: 13px;
    /*cursor: pointer;*/
    overflow:hidden;
    }
.innerbox{
    overflow-x: hidden;
    overflow-y: auto;
    color: #000;
    font-size: .7rem;
    font-family: "\5FAE\8F6F\96C5\9ED1",Helvetica,"黑体",Arial,Tahoma;
    height: 100%;
    }
/*滚动条样式*/
.innerbox::-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;
    }
.innerbox::-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);
    }
.innerbox::-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);
    }