.panel-title span.icon {
    float: right;
    width: 16px;
    height: 16px;
}
a[aria-expanded="false"] span.icon {
    /*background-image: url("images/ui-icons_444444_256x240.png");*/

    background-image: url('../../images/common/ui-icons_ffffff_256x240.png');
    background-position: -15px -130px;
}
a[aria-expanded="true"] span.icon {
    
    background-image: url('../../images/common/ui-icons_ffffff_256x240.png');
    background-position: -47px -128px;
}