change image size jQueryMobile list

change image size jQueryMobile list

I can not change the jquery mobile css to resize an image inside a list , I put the image to a width 20 % and high auto.

<!DOCTYPE html>

<html>
<head>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="http://code.jquery.com/mobile/1.3.1/jquery.mobile-1.3.1.min.css" />
    <script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
    <script src="http://code.jquery.com/mobile/1.3.1/jquery.mobile-1.3.1.min.js"></script> 
</head>

<body>

<div data-role='page'>

   
    <div data-role='content'>
        <ul data-role='listview'>
            <li><a href='#'><img src='img/6ac994c32671ecc26.jpg'><h3>cars</h3><p>text</p></a>
            <li><a href='#'><img src='img/6ac994c32321ecc26.jpg'><h3>hotels</h3><p>text</p></a>
            <li><a href='#'><img src='img/6ac994c3441ecc26.jpg'><h3>restaurant</h3><p>text</p></a>
        </ul>
    </div>
   

</div>

</body>
</html>