Resize Div based on Inner Div

by Yusril Maulidan Raji

HTML

<div id="main-container" style="">
  <div id="sub-container" style="">
  
  
  </div>
  <br class="clear" />
</div>

CSS

#main-container {
  border:1px solid black;

  width:100px;
  background: blue;
}
#sub-container {
  border:1px solid black;
  height:250px;
  width:50px;
  background: red;
}
.clear { clear: both; }