.u6-btn-fuse-ani {
    position: absolute;
    width: 100%;
    height: 100%;
    left: 0;
    top: 0;
    opacity: 15%;
    background-color: orange;
    box-shadow: 0 0 10px orange;
    animation: u6-btn-fuse-blinker 1s linear infinite;
}

@keyframes u6-btn-fuse-blinker {
    50% {
        opacity: 0;
    }
}