CodePen

HTML

            
              
<div id="nogap"></div>
    <!--dont want gap between two divs-->
<div id="banner">
  <div id="banner_inner"></div>
  <div>

            
          
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↑ Insert the most common viewport meta tag

CSS

            
              #banner{
  width:500px;
  height:199px;
  background:#ccc;
  border-top:1px solid #ccc;
  }

#banner_inner{
  width:480px;
  height:180px;
  background:red;
  margin:10px;
  }

#nogap{
   width:500px;
    height:50px;
  background:green;
}
            
          
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JS

            
              
            
          
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