Google's CDN website displays the minified version for js but unminified version for css: https://developers.google.com/speed/libraries/devguide#jqueryui
jQuery UI
snippet: <link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.3/themes/smoothness/jquery-ui.css" />
<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.3/jquery-ui.min.js"></script>
site: jqueryui.com
versions: 1.11.3, 1.11.2, 1.11.1, 1.11.0, 1.10.4, 1.10.3, 1.10.2, 1.10.1, 1.10.0, 1.9.2, 1.9.1, 1.9.0, 1.8.24, 1.8.23, 1.8.22, 1.8.21, 1.8.20, 1.8.19, 1.8.18, 1.8.17, 1.8.16, 1.8.15, 1.8.14, 1.8.13, 1.8.12, 1.8.11, 1.8.10, 1.8.9, 1.8.8, 1.8.7, 1.8.6, 1.8.5, 1.8.4, 1.8.2, 1.8.1, 1.8.0, 1.7.3, 1.7.2, 1.7.1, 1.7.0, 1.6.0, 1.5.3, 1.5.2
note: This library depends on jQuery. You must also load jQuery before loading this module. Version 1.8.3 is not hosted due to its short life, and the alias 1.8.3 actually loads 1.8.4.
For a minified css, use: https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.3/themes/smoothness/jquery-ui.min.css