界面规范7-可左右拖动的分割条

代码：<el-divider direction="vertical" @mousedown="startDrag"></el-divider>
css设置
::v-deep .el-divider--vertical{display: inline-block;background: url('/images/button_1.gif') no-repeat center center;width: 6px;height: calc(100% - 40px);margin: 0;cursor: ew-resize;vertical-align: middle;position: relative;background-color: #d2d2d2;align-items: center;
}
按钮按下后，需要改变背景色：#8dccff