保持一个拆分容器面板固定宽度？

.container {
  display: grid;
  grid-template-columns: 200px auto;
}

.left {
  grid-column: 1;
}

.right {
  grid-column: 2;
}

.container {
  display: flex;
}

.left {
  width: 200px;
}

.right {
  flex: 1;
}

<div class="container">
  <div class="row">
    <div class="col-md-2">左侧内容</div>
    <div class="col-md-10">右侧内容</div>
  </div>
</div>