修改滚动条默认样式

.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);
        }