packer-cn/website/source/assets/stylesheets/_columns.scss

#main-content{
  display: flex;
  flex: 1;

  #sidebar,
  .docs-body{
    flex: 1;
  }
}

@media (max-width: 992px) {
  #main-content{
    #sidebar{
      max-width: 280px;
    }
  }
}

@media (max-width: 768px) {
  #main-content{
    flex-direction: column;

    #sidebar,
    .docs-body{
      width: 100%;
      max-width: none;
    }

    #sidebar{
      li {
        &:last-child{
          border-bottom: none;
        }
        > *{
          margin-left: 0;
        }
      }
    }

    .docs-content{
      padding: 40px 0;
    }
  }
}