message: fix workbench flex issue
diff: flex: 1;
  display: flex;
  flex-direction: row;
  + min-width: 0;
  .model {
  flex: 9;
  background-color: @light-bg;
  - flex-shrink: 0;
  display: flex;
  flex-direction: column;
  + min-width: 0;
  }
  .config {
  background-color: @white;
  border-left: 1px solid @border-color-base;
  box-shadow: @left-side-box-shadow;
  - flex-shrink: 0;
  display: flex;
  flex-direction: column;
  }
  