Hi,
I am using following css for displaying a spinner while waiting for some ajax response.

.json-overlay {
background: #e9e9e9;
background-image: url('/images/loader.gif');
background-repeat: no-repeat;
background-position: center;
display: none;
position: absolute;
top: 0;
right: 0;
bottom: 0;
left: 0;
opacity: 0.5;
}

it was working fine before integrating MegaCourse theme. but after integration, the spinner does not show at all.
Please help?