CodePen

HTML

            
              <header>
  <h2>Props</h2>
</header>
            
          
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CSS

            
              header {
  background: #ddd;
  max-width: 400px;
  text-align: center;
  
  margin: auto;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: table;
}
 
/* Clearfix */
header:after {
  content: 'clear fix';
  display: block;
  height: 0;
  visibility: hidden;
  word-spacing: 9999rem; 
}
            
          
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JS

            
              
            
          
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