#0003 CSS Only Collapse

source: https://codepen.io/Hazar/pen/bEbKpv

Try it

Code

the html

<label for="cbToggleVisibility" class="toggle-label" role="button">Click me!</label>

<div class="content-container">
<input type="checkbox" id="cbToggleVisibility">

<div class="target">
<h1>some content</h1>
<p>Some awesome text, not that lorep ipsum mumbo jumbo</p>
</div>
</div>

the css

.toggle-label {
    border: 2px solid black;
    padding: 15px;
    cursor: pointer;
}

#cbToggleVisibility {
    position: absolute;
    left: -999999999px;
}

.target {
    display: none;
}

#cbToggleVisibility:checked ~ .target {
    display: block;
}