JSFiddle - React, Tailwind, and code Playground

HTML

<div class="accordion">
    <fieldset class="section" id="id1">
        <legend class="section-header"> 
            <a href="#id1">Section 1</a>
        </legend>
        <div class="section-content">
            Section 1 content
        </div>
    </fieldset>
    <fieldset class="section" id="id2">
        <legend class="section-header"> 
            <a href="#id2">Section 2</a>
        </legend>
        <div class="section-content">
            Section 2 content
        </div>
    </fieldset>
</div>

CSS

.accordion .section {
    margin: 1em;
}
.accordion .section-header a {
    text-decoration: none;
    color: gray;
}
.accordion .section:hover .section-header a {
    color: red;
}
.accordion .section .section-content {
    display: none;
}
.accordion .section:target .section-content {
    display: block;
}
.accordion .section:target {
    border: 2px solid navy;
}
.accordion .section:target .section-header a {
    color: navy;
    cursor: default;
}
.accordion .section-header a:before {
    content:"\25BA\0000a0"
    /* unicode triangle pointing right */
}
.accordion .section:target .section-header a:before {
    content:"\25BC\0000a0"
    /* unicode triangle pointing down */
}