JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
  <div id="topo"></div>
  <div id="conteudo"></div>
  <div id="rodape"></div>
</div>

CSS

*{margin: 0; padding: 0;}
#container{
    width: 80%;
    margin: 0 auto;
}

#topo{
    width: 100%;
    height: 100px;
    background: blue;
}

#conteudo{
    width: 100%;
    height: 500px;
    background: gray;
}

#rodape{
    width: 100%;
      height:100px;
    /* Cor de fundo da div */
    background-color:#C3C;
}