.flex-container {
  display: flex;
  width: 100%;

  .tree-area {
    flex: 0 0 200px;
    overflow: auto;
  }

  .list-area {
    flex: 1;
    overflow: auto;
    margin-left: 20px;
  }
}

.three-column-layout {
  height: calc(100vh - 35px);

  .el-aside {
    margin-right: 20px;
    padding-top: 20px;
    background-color: #FFFFFF;
    box-shadow: 0px 1px 8px 0px #00000019;

  }

  .el-main {
    padding: 20px 0 0 20px;
    border-radius: 6px;
    background: #FFFFFF;
    box-shadow: 0px 1px 8px 0px #00000019;
  }
}