JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
  <header id="header"></header>
  <div id="container">
    <div id="main"></div>
    <aside id="left"></aside>
  </div>
  <footer id="footer"></footer>
</div>

CSS

header {
    background:#BF7972;
    min-height:100px;
}

#main,
#left {
    float:left;
    position:relative;
    min-height:500px;
}

#left {
    left:-75%;
    width:25%;
    background:#8B72BF;
}

#main {
    left:25%;
    width:75%;
    background:#729DBF;
}

#container:after {
    clear:both;
    display:block;
    content:"";
}

footer {
    min-height:50px;
    background:#BF72AE;
}