title: How to apply remaining width to a div aside sidebar having specific width
body: <p>what I intend to do is following. I have a <code>div#sidebar</code> with specific width on the right. This sidebar <code>div</code> takes up place on the right. What I now want to do is to apply the remaining width to another <code>div#left</code> on the left of sidebar.</p>
  
  <p>But it does not work properly, since the <code>div</code>  under the sidebar <code>div</code>. I want the <code>div</code> to be <code>100% width</code> to the margin of sidebar. Not the whole side.
  I made an image to explain it better:
   <img src="https://i.stack.imgur.com/Vehva.png" alt="desired output"></p>
  
  <p>Following is the css i currently have:</p>
  
  <pre><code>#sidebar {
     height: 100%;
     width: 342px;
     float:right;
  }
  
  #left {
     float: left;
     width: 100%;
     height: 100%;
  }
  </code></pre>
  
  <p>Hope you get my point. Thanks</p>