<div class="container">
  <div class="content clearfix">
    <div class="right">
      我是右侧的内容,我的颜色来自内部容器 .content
      <br />
      <br />
      <br />
      <br />
      我很长
    </div>
    <div class="left">
      我是左侧的内容,我的颜色来自最外层容器 .container
    </div>
  </div>
</div>
.container {width: 500px; margin: 0 auto; background-color: skyblue;}
.content {margin-left: 200px; background-color: pink;}
.right {float: left; width: 100%;}
.left {float: left; width: 200px; margin-left: -500px;}

.clearfix::before, .clearfix::after {content: ''; display: table;}
.clearfix::after {clear: both; overflow: hidden;}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.