.shk {
    transform: translate3d(0, 0, 0);
    backface-visibility: hidden;
    animation-name: shakeMe;
    animation-duration: 5s;
    animation-iteration-count: infinite;
    animation-timing-function: linear;
}

@keyframes shakeMe {
    2%, 18% {
        transform: translate3d(-5px, 0, 0);
    }

    4%, 16% {
        transform: translate3d(5px, 0, 0);
    }

    6%, 10%, 14% {
        transform: translate3d(-5px, 0, 0);
    }

    8%, 12% {
        transform: translate3d(5px, 0, 0);
    }
    
    18.1% {
        transform: translate3d(0px, 0, 0);
    }
}