jQWidgets uses a pair of css files - jqx.base.css and jqx.[theme name].css. The base stylesheet creates the styles related to the widget's layout like margin, padding, border-width, position. The second css file applies the widget's colors and backgrounds. The jqx.base.css should be included before the second CSS file.
Below is the list of CSS classes used by jqxMaskedInput.<script type="text/javascript"> $(document).ready(function () { // Create jqxMaskedInput $("#jqxmaskedinput").jqxMaskedInput({ width: '250px', height: '25px', theme: 'summer', mask: '(###)###-####' }); });</script>
<!DOCTYPE html><html lang="en"><head> <title id='Description'>jQuery Masked Input CSS Styling Sample</title> <link rel="stylesheet" href="../../jqwidgets/styles/jqx.base.css" type="text/css" /> <link rel="stylesheet" href="../../jqwidgets/styles/jqx.summer.css" type="text/css" /> <script type="text/javascript" src="../../scripts/jquery-1.11.1.min.js"></script> <script type="text/javascript" src="../../jqwidgets/jqxcore.js"></script> <script type="text/javascript" src="../../jqwidgets/jqxmaskedinput.js"></script> <script type="text/javascript"> $(document).ready(function () { // Create jqxMaskedInput $("#jqxmaskedinput").jqxMaskedInput({ width: '250px', height: '25px', theme: 'summer', mask: '(###)###-####' }); }); </script><script async src="https://www.googletagmanager.com/gtag/js?id=G-2FX5PV9DNT"></script><script>window.dataLayer = window.dataLayer || [];function gtag(){dataLayer.push(arguments);}gtag('js', new Date());gtag('config', 'G-2FX5PV9DNT');</script></head><body class='default'> <div> Phone Number</div> <div id='jqxmaskedinput'> </div></body></html>