img {
    height: 150px;
    margin: 10px;

    opacity: 0;
}

.loaded {
    -webkit-animation: fadein .5s;
    -moz-animation: fadein .5s;
    -o-animation: fadein .5s;
    animation: fadein .5s;

    opacity: 1;
}

@keyframes fadein {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@-moz-keyframes fadein {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@-webkit-keyframes fadein {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@-ms-keyframes fadein {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@-o-keyframes fadein {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.hidden {
    display: none;
}