#slider {
    overflow: hidden;
}

#slider figure {
    position: relative;
    width: 400%;
    margin: 0;
    left: 0;
    animation: 40s slider infinite;
}

#slider figure img {
    width: 25%;
    float: left;
}

@keyframes slider {
    0% {
        left: 0;
    }
    20% {
        left: 0;
    }
    25% {
        left: -100%;
    }
    45% {
        left: -100%;
    }
    50% {
        left: -200%;
    }
    70% {
        left: -200%;
    }
    75% {
        left: -300%;
    }
    95% {
        left: -300%;
    }
    100% {
        left: -300%;
    }
}