JSFiddle - React, Tailwind, and code Playground

HTML

<div class="slide0"><h3>Category 1<div class="tri0"></div></h3></div>
<div class="view0">
    This text in this category is revealed already when the page loads.
    
</div>

<div class="slide1"><h3>Category 2<div class="tri1"></div></h3></div>
<div class="view1">
    The text in this category is hidden until user clicks the Category 2 heading.
    
</div>

CSS

.slide0, .slide1 {
    cursor: pointer;
    max-width: 1180px;
    margin-left: auto;
    margin-right: auto;
    width: 90%;
    border: 1px solid black;
    background-color: #FFFF99;
    margin-bottom: 20px;
}

h3 {
    font-size: 16px;
    margin: 1px auto;
    padding: 10px 15px 10px 10px;
}

.tri0 {
    width: 0;
    height: 0;
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-top: 10px solid black;
    float: right;
    -moz-transition: -moz-transform .3s;
    -webkit-transition: -webkit-transform .3s;
    -o-transition: -o-transform .3s;
    transition: transform .3s;
}

.tri1 {
    width: 0;
    height: 0;
    border-top: 10px solid transparent;
    border-bottom: 10px solid transparent;
    border-right: 10px solid black;
    float: right;
    -moz-transition: -moz-transform .3s;
    -webkit-transition: -webkit-transform .3s;
    -o-transition: -o-transform .3s;
    transition: transform .3s;
}

.toggle0 {
    -moz-transform: rotate(90deg);
     -o-transform: rotate(90deg);
    -webkit-transform: rotate(90deg);
    transform: rotate(90deg);

}

.toggle1 {
    -moz-transform: rotate(-90deg);
    -o-transform: rotate(-90deg);
    -webkit-transform: rotate(-90deg);
    transform: rotate(-90deg);
}

JavaScript

$(document).ready(function(){
    $("div.view1").hide();
    
    //watch for clicks on the "slide0" banner
    $("div.slide0").click(function(){
        $("div.view0").slideToggle(400);
        $("div.tri0").toggleClass("toggle0");
    });
    
        
    //watch for clicks on the "slide1" banner
    $("div.slide1").click(function(){
        $("div.view1").slideToggle(400);
        $("div.tri1").toggleClass("toggle1");
    });
    
});