//index.html
<div id="ball"></div>
//main.css
#ball {
width: 120px;
height: 120px;
border-radius: 120px;
margin: 150px auto 0 auto;
}
$(document).ready(function(){
alert('ready');
});
$(document).ready(function(){ $('.ball').on('click',function(){
alert('touch');
}); });
$('.ball').on('mousedown',function(){
$(this).addClass('big');
});
$('.ball').on('mouseup',function(){ $(this).removeClass('big'); });
transition: 0.3s ease-in;