@keyframes pulsing
{
    0% {background-color: rgba( 255, 0, 0, 1 );}
    50% {background-color: rgba( 255, 0, 0, 0.3 );}
    100% {background-color: rgba( 255, 0, 0, 1 );}
}

@keyframes pulsing-opacity
{
    0% {opacity: 1;}
    50% {opacity: 0.3;}
    100% {opacity: 1;}
}