.horizontally {
    height: 205px;
    overflow: hidden;
    position: relative;
}

.horizontally .inner {
    position: absolute;
    width: 100%;
    height: 100%;
    text-align: center;
    /* Starting position */
    -moz-transform: translateX(40%);
    -webkit-transform: translateX(40%);
    transform: translateX(40%);
    /* Apply animation to this element */
    -moz-animation: horizontally 5s linear infinite alternate;
    -webkit-animation: horizontally 5s linear infinite alternate;
    animation: horizontally 5s linear infinite alternate;
}
/* Move it (define the animation) */
@-moz-keyframes horizontally {
    0% {
        -moz-transform: translateX(40%);
    }

    100% {
        -moz-transform: translateX(-40%);
    }
}

@-webkit-keyframes horizontally {
    0% {
        -webkit-transform: translateX(40%);
    }

    100% {
        -webkit-transform: translateX(-40%);
    }
}

@keyframes horizontally {
    0% {
        -moz-transform: translateX(40%); /* Browser bug fix */
        -webkit-transform: translateX(40%); /* Browser bug fix */
        transform: translateX(40%);
    }

    100% {
        -moz-transform: translateX(-40%); /* Browser bug fix */
        -webkit-transform: translateX(-40%); /* Browser bug fix */
        transform: translateX(-40%);
    }
}