JSFiddle - React, Tailwind, and code Playground

HTML

<div id="header">
      100 % Höhe mit fixiertem Header und Footer
    </div>  
    <div id="content">
      <p>
      Fülltext für den Content... <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      Content <br /><br /><br />
      last Content <br /><br /><br />
      </p>
    </div>

CSS

#header {
    position: fixed;
    top: 0;
    left:0;
    width: 100%;
    height:40px;
    background: #CCE34A;
}