<div class="test test-1">
 <div class="scrollbar"></div>
</div>

 .test {
 width : 50px;
 height : 200px;
 overflow: auto;
 float : left;
 margin : 5px;
 border : none;
 }
 .scrollbar {
 width : 30px;
 height: 300px;
 margin: 0 auto;
 }
 .test-1::-webkit-scrollbar {
 /*滚动条整体样式*/
 width : 10px; /*高宽分别对应横竖滚动条的尺寸*/
 height: 1px;
 }
 .test-1::-webkit-scrollbar-thumb {
 /*滚动条里面小方块*/
 border-radius: 10px;
 box-shadow : inset 0 0 5px rgba(0, 0, 0, 0.2);
 background : #535353;
 }
 .test-1::-webkit-scrollbar-track {
 /*滚动条里面轨道*/
 box-shadow : inset 0 0 5px rgba(0, 0, 0, 0.2);
 border-radius: 10px;
 background : #ededed;
 }

.test-5::-webkit-scrollbar {
 /*滚动条整体样式*/
 width : 10px; /*高宽分别对应横竖滚动条的尺寸*/
 height: 1px;
 }
 .test-5::-webkit-scrollbar-thumb {
 /*滚动条里面小方块*/
 border-radius : 10px;
 background-color: skyblue;
 background-image: -webkit-linear-gradient(
 45deg,
 rgba(255, 255, 255, 0.2) 25%,
 transparent 25%,
 transparent 50%,
 rgba(255, 255, 255, 0.2) 50%,
 rgba(255, 255, 255, 0.2) 75%,
 transparent 75%,
 transparent
 );
 }
 .test-5::-webkit-scrollbar-track {
 /*滚动条里面轨道*/
 box-shadow : inset 0 0 5px rgba(0, 0, 0, 0.2);
 background : #ededed;
 border-radius: 10px;
 }