Pure CSS collapsible (with on click) containers/elements/whateva.
HTML Code:
<div id="elem"></div>
<a href="#" class="par cac1">Tab 1</a>
<a href="#" class="par cac2">Tab 2</a>
<a href="#" class="par cac3">Tab 3</a>
<h1 class="zzz1">ELEMENT 1</h1>
<h1 class="zzz2">ELEMENT 2</h1>
<h1 class="zzz3">ELEMENT 3</h1>
CSS Code:
h1 {display: none; }
a.par:focus {color: red}
a.par.cac1:focus ~ h1.zzz1 { display: block; color: blue }
a.par.cac2:focus ~ h1.zzz2 { display: block; color: blue }
a.par.cac3:focus ~ h1.zzz3 { display: block; color: blue }