JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>Column 1</li>
    <li>Column 2</li>
    <li>Column 3</li>
    <li class="balka"></li>
</ul>

CSS

ul {
    width: 500px;
    text-align: justify;
    list-style-type: none;
}

li {
    background: gray;
    display: inline-block;
    height: 300px;
    border: solid 1px black;
    width:  100px;
}
.balka {
    width: 100%;
    height: 0;
    border: none;
}