UI---div加漂亮滚动条

.activity::-webkit-scrollbar {         /*滚动条整体样式*/
    width:3px;
    height:3px;
}
.activity::-webkit-scrollbar-thumb {   /*滚动条里面小方块样式*/
    border-radius:100px;
    -webkit-box-shadow:inset 0 0 5px rgba(0,0,0,0.2);
    background:rgba(0,0,0,0.1);;
} 
.activity::-webkit-scrollbar-track {   /*滚动条里面轨道样式*/
    -webkit-box-shadow:inset 0 0 5px rgba(0,0,0,0.2);
    border-radius:0;
    background:rgba(0,0,0,0.1);
}