css 修改滚动条样式

.treeView {
     
  	width: 155px;
 	position: fixed;
    overflow-y: auto;
    height: 400px;
    border:1px solid #f2f2f2;
}
.treeView::-webkit-scrollbar {
     
    width: 4px; 
}
.treeView::-webkit-scrollbar-thumb {
     
    border-radius: 10px;
    background: #bbb;
}
.treeView::-webkit-scrollbar-track {
     
    border-radius: 0;
    background: #eee;
}