JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>Tab 1</li>
    <li>Tab 2</li>
    <li>Tab 3</li>
</ul>
<ul>
    <li>Tab 4</li>
    <li>Tab 5</li>
    <li>Tab 6</li>
</ul>

CSS

ul {
    border: 1px sold black;
}