Multiple CSS collapse/expand in same page - html

Question

I've CSS collapse/expand code refereed from # https://codepen.io/peternguyen/pen/hICga/ . But the problem with my code is that they won't work in same page. I intended to use it at Wordpress page.
Have a look at my code. Thanks.
input {
display: none;
visibility: hidden;
}
label {
font-weight: bold;
font-size: 15px;
display: block;
color: #666;
text-decoration: underline;
}
label:hover {
color: #000;
}
#expand {
height: 0px;
overflow: hidden;
transition: height 0.5s;
color: #000;
}
section {
padding: 0 20px;
}
#toggle:checked ~ #expand {
height: auto;
}
<input id="toggle" type="checkbox">
<label for="toggle">Hidden Kitten</label>
<div id="expand">
<section>
<p>mew</p>
</section>
</div>
<input id="toggle" type="checkbox">
<label for="toggle">Hidden Kitten</label>
<div id="expand">
<section>
<p>mew</p>
</section>
</div>

Answer 1

I made all id-specific parts independent and changed ~ to +.
Working codepen
Code:
#import url(https://fonts.googleapis.com/css?family=Open+Sans:400,700);
body {
font-family: "Open Sans", Arial;
background: #CCC;
}
main {
background: #EEE;
width: 600px;
margin: 20px auto;
padding: 10px 0;
box-shadow: 0 3px 5px rgba(0, 0, 0, 0.3);
}
h2 {
text-align: center;
}
p {
font-size: 13px;
}
input {
display: none;
visibility: hidden;
}
label {
display: block;
padding: 0.5em;
text-align: center;
border-bottom: 1px solid #CCC;
color: #666;
}
label:hover {
color: #000;
}
label::before {
font-family: Consolas, monaco, monospace;
font-weight: bold;
font-size: 15px;
content: "+";
vertical-align: text-top;
display: inline-block;
width: 20px;
height: 20px;
margin-right: 3px;
background: radial-gradient(ellipse at center, #CCC 50%, transparent 50%);
}
.expand {
height: 0px;
overflow: hidden;
transition: height 0.5s;
background: url(http://placekitten.com/g/600/300);
color: #FFF;
}
section {
padding: 0 20px;
}
.toggle:checked+label+.expand {
height: 250px;
}
.toggle:checked+label::before {
content: "-";
}
<main>
<h2>CSS Expand/Collapse Section</h2>
<input id="toggle" type="checkbox" checked class="toggle">
<label for="toggle">Hidden Kitten</label>
<div class="expand">
<section>
<p>mew</p>
</section>
</div>
<section>
<h3>Other content</h3>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas porta non turpis faucibus lobortis. Curabitur non eros rutrum, gravida felis non, luctus velit. Ut commodo congue velit feugiat lobortis. Etiam nec dolor quis nulla bibendum blandit
vitae nec enim. Maecenas id dignissim erat. Aenean ac mi nec ante venenatis interdum quis vel lacus.
</p>
<p>Aliquam ligula est, aliquet et semper vitae, elementum eget dolor. In ut dui id leo tristique iaculis eget a dui. Vestibulum cursus, dolor sit amet lacinia feugiat, turpis odio auctor nisi, quis pretium dui elit at est. Pellentesque lacus risus, vulputate
sed gravida eleifend, accumsan ac ante. Donec accumsan, augue eu congue condimentum, erat magna luctus diam, adipiscing bibendum sem sem non elit.</p>
</section>
<input id="toggle2" type="checkbox" checked class="toggle">
<label for="toggle2">Hidden Kitten 2</label>
<section class="expand">
test
</section>
</main>