Interference Showcase

This fiddle presents an example, of how a common JavaScript solution for a slider-widget fails in consequence of an apparently unrealted CSS-rule.

by 1UnitedPower

HTML

<script src="//code.jquery.com/ui/1.10.4/jquery-ui.js"></script>
<link rel="stylesheet" href="//code.jquery.com/ui/1.10.4/themes/smoothness/jquery-ui.css">
<script src=""></script>
<div id="slider"></div>

CSS

a::before{
    content: '->';
    background-color: white;
    width: 4em;
    display: block;
}

JavaScript

$('#slider').slider();