CSS continuous animation for images

Hi,

I’m trying to make the images on this page to always slowly rotate:

Home Creative

Specifically this one:
src=”https://themes.ishyoboy.com/no8/wp/wp-content/uploads/2014/09/cloud_image.png”

I’ve tried to use this code in the custom CSS box and putting the class name in the image extra css class field but its not working for some reason:

.imagerotate {
position: absolute;
top: 50%;
left: 50%;
width: 120px;
height: 120px;
margin:-60px 0 0 -60px;
-webkit-animation:spin 4s linear infinite;
-moz-animation:spin 4s linear infinite;
animation:spin 4s linear infinite;
}
@-moz-keyframes spin { 100% { -moz-transform: rotate(360deg); } }
@-webkit-keyframes spin { 100% { -webkit-transform: rotate(360deg); } }
@keyframes spin { 100% { -webkit-transform: rotate(360deg); transform:rotate(360deg); } }

Can you please help with this?
Thanks.