JSFiddle - React, Tailwind, and code Playground

HTML

<header></header>
<div class="container">
    <div class="aside-left">
        <p>sdfsdfs</p>
          <p>sdfsdfs</p>
          <p>sdfsdfs</p>
          <p>sdfsdfs</p>
          <p>sdfsdfs</p>
          <p>sdfsdfs</p>
          <p>sdfsdfs</p>
          <p>sdfsdfs</p>
          <p>sdfsdfs</p>
          <p>sdfsdfs</p>
          <p>sdfsdfs</p>
          <p>sdfsdfs</p>
        
    </div>
    <div class="container-mid">sdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdfsdfgsdfg<br><br>sdf</div>
    <div class="push"></div>
    <footer></footer>
</div>

CSS

html,body{
    height:100%;
    background:#ffaaaa;
    margin:0;
}
header{
    background: #2f3d4c;
    overflow: hidden;
    position: fixed;
    top: 0;
    right: 0;
    left: 0;
    z-index: -1;
    width: 100%;
    height: 75px;
}
.container{
    min-height:100%;
    position:relative;
}
.aside-left{
    background-color: rgba(255, 255, 255, 0.8);
    position: fixed;
    left: 0;
    top: 75px;
    bottom: 55px;
    width: 192px;
    overflow: auto;
    z-index: 50;
}
.container-mid{
    margin-left: 192px;
}
.push,footer{
    height: 55px;
}
footer {
    position: fixed;
    right: 0;
    bottom: 0;
    left: 0;
    overflow: hidden;
    color: #ffffff;
    width: 100%;
    background: #2f3d4c;
    z-index: 100;
}