JSFiddle - React, Tailwind, and code Playground

HTML

<header><ul>
    <li>sdasasdasdasdasdasd</li>
</ul></header>

CSS

header {
height: 150px;
background: #CC66FF;
overflow: auto;
margin-bottom: 1%;
margin-top: 2%;
border-radius: 5px;
}
header h1 {
height: 30%;
float: left;
margin-left: 1%;
}
ul {
margin: 9% 0 0 0;
padding: 0;
}
ul li {
list-style-type: none;
background: #666;
display:block;
color: white;
border-radius: 5px;
}