CodePen

HTML

            
              <div id="container">
  <div id="sidebar">
    <p>This is the sidebar.</p>
    <p> Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin eu velit quis metus imperdiet euismod. Nam varius iaculis odio at auctor. Sed erat ipsum, dictum sit amet semper vel, dignissim sed urna. Sed non risus nulla. Suspendisse varius neque nec felis tempus consectetur. Morbi tempor, nunc vel sollicitudin adipiscing, leo urna eleifend purus, sed adipiscing massa nulla eu purus. Pellentesque in purus tortor. Pellentesque in nisl in nisi viverra bibendum. Proin consectetur mauris a enim pharetra ornare. Curabitur nec enim arcu, vel pellentesque purus. Quisque sit amet est tellus. Etiam elementum lacinia elementum. Nullam est urna, viverra lobortis venenatis eu, sagittis sed diam. Praesent hendrerit urna sed lectus elementum rutrum. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Sed hendrerit tristique rhoncus.</p>
  </div>
  <div id="content">
    <h1>Main Content</h1>
    <p>This is the flexible main content area.</p>
  </div>
  <div id="footer">
    <p>Footer stuff here.</p>
  </div>
</div>
            
          
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↑ Insert the most common viewport meta tag

CSS

            
              #container {
  background: #b00b00;
  border-left: 300px solid #bada55;
}

#sidebar {
  float: left;
  width: 280px;
  padding: 10px;
  margin-left: -300px;
}

#content {
  padding: 10px;
}

#footer {
  clear: both;
  background: #333;
  margin-left: -300px;
  padding: 10px;
}
            
          
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JS

            
              
            
          
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