JSFiddle - React, Tailwind, and code Playground

by gabrieleromanato

HTML

<ul id="folder">
   <li>
       <a href="#sub-1">1</a><span>Folder 1</span>
           <ul id="sub-1">
               <li>A</li>
               <li>B</li>
               <li>C</li>
           </ul>
  </li>
  <li>
    <a href="#sub-2">1</a><span>Folder 2</span>
           <ul id="sub-2">
               <li>D</li>
               <li>E</li>
               <li>F</li>
           </ul>
 </li>
</ul>

CSS

#folder {
    margin: 2em;
}

#folder > li {margin-bottom: 0.5em;}

#folder > li > a {
    display: inline-block;
    width: 16px;
    height: 16px;
    text-indent: -1000em;
    background: url(https://lh3.googleusercontent.com/-sKBm8juxZq8/T7NzWBuLoRI/AAAAAAAABAg/jWO7W3elBug/s160/icons.png) no-repeat 0 -32px;
    margin-right: 5px;
}

#folder > li > a:active {background-position: 0 -16px;}



#folder > li > a + span {
    display: inline-block;
    height: 16px;
    line-height: 16px;
    padding-left: 20px;
    font-weight: bold;
    background: url(https://lh3.googleusercontent.com/-sKBm8juxZq8/T7NzWBuLoRI/AAAAAAAABAg/jWO7W3elBug/s160/icons.png) no-repeat 0 0;
}

#folder > li ul {
    margin-left: 2.5em;
    line-height: 1.4;
    display: none;
}

#folder > li ul:target {
    display: block;
}