PSFPortal/scss/defaults.scss

.notification-shake {
    animation: shake 0.82s cubic-bezier(.36,.07,.19,.97) both;
    transform: translate3d(0, 0, 0);
}

@keyframes shake {
    10%, 90% {
        transform: translate3d(-1px, 0, 0);
    }

    20%, 80% {
        transform: translate3d(2px, 0, 0);
    }

    30%, 50%, 70% {
        transform: translate3d(-4px, 0, 0);
    }

    40%, 60% {
        transform: translate3d(4px, 0, 0);
    }
}