JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
<li>1</li>
<li>2
  <ul>
  <li>a</li>
  <li>b</li>
  <li>c</li>
  </ul>
</li>
<li>3
    </li>
</ul>

SCSS

ul {
    margin:0;
    padding:0;
}
li {    
    margin:0;
    padding:0;
    display:inline-block;
    vertical-align:top;
    border:1px solid red;
    ul {
      width:10em;
    }
    li {
       display:block;  
       border-color:green;
    }
}