I use jquery mobile to generate my buttons and I have a CSS code below to change its design but no matter what value i put in width and height the size of the button doesn\'
Live Example:
JS:
// For all buttons use something like this
$('.ui-btn').css('width','50%');
// For individual buttons use something like this
$('#theButton1').parent().css('width', '75%');
// Or this for HREF data-role buttons
$('#hrefButton4').css('width', '45%');
UPDATE: (I think this is what you're looking for)
// this changes the height for all buttons
$('.ui-btn-text').css('font-size','50px');
// This changes the height for a single element
$('#hrefButton3').children().children().css('font-size','30px');
HTML: