Customizing a right or left panel you will need to change 3 CSS classes set by JQM. The animation, the panel, and the inner part of the panel which is were the content is in. An easier way is to create custom overlay box.
Demo
https://jsfiddle.net/bz649m86/
Html
<div class="box"><a class="close">Close</a></div>
CSS
.box {
position:fixed; // a fixed position is used for the box
top:0; // placed at the top of the screen
right:-100%; // with a minus position setting on the right side of the screen so its hidden from view
background-color: blue;
width: 100%; //with a width of the whole screen, but it can be any width
display: block; //displayed in block format
z-index: 999999; // above the header when in view
overflow: hidden; // if you don't require scrolling within the box
height:40px; // the height size required
//the transition settings are not needed but makes the animation of the panel much smoother.
-webkit-transition: all .3s ease;
-moz-transition: all .3s ease;
-ms-transition: all .3s ease;
-o-transition: all .3s ease;
transition: all .3s ease;
}
Jquery
// animate on click to bring the box in to view
$(document).on("click", ".pannel", function () {
$('.box').animate({
'right': "0%"
}, 300);
})
// and out of view when closed
$(document).on("click", ".close", function () {
$('.box').animate({
'right': "-100%"
}, 300);
})
As a side note, with this method you can have a custom panel (overlayed) displayed anywhere on the screen.
In this demo the box comes from top of the screen
https://jsfiddle.net/Lqxp2ewb/