JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
</ul>

CSS

ul, li{
    list-style:none;
    margin:0;
    padding:0;
    box-sizing:border-box;
    height:10px;
}
li{
    float:left;
    border:1px solid red;
    width:100px;
}
li:last-child{
    float:none;
    width:auto;
    overflow:hidden;
    min-width:200px;
}