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HTML 

              
                div.cards
    for i in [1, 2, 3, 4, 5, 6, 7, 8, 9]
        div.card
            div.card-front
                h2.card-title Card Title
            div.card-back
                div.card-back-wrapper
                    p Lorem ipsum dolor sit amet, consectetur adipisicing elit. Tempora nesciunt quod dolores aliquid repudiandae ipsa recusandae quam dolore, repellendus eligendi dignissimos voluptas iure sunt atque odio, cupiditate necessitatibus, fugiat iusto quisquam esse omnis laborum facere. Temporibus natus animi tempore. Labore!
!

CSS 

              
                $nb-cards: 9;
$nb-columns: 3;
$nb-rows: ceil($nb-cards / $nb-columns);
$transition-duration: 300ms;

$images: (
    "http://lorempixel.com/600/800/nature",
    "http://lorempixel.com/600/800/sports",
    "http://lorempixel.com/600/800/city",
    "http://lorempixel.com/600/800/business",
    "http://lorempixel.com/600/800/technics",
    "http://lorempixel.com/620/800/city",
    "http://lorempixel.com/620/800/nature",
    "http://lorempixel.com/620/800/business",
    "http://lorempixel.com/620/800/sports"
);

body {
    background-color: #1d1f20;
    -webkit-transform: translate3d(0,0,0);
}

.cards {
    width: 100%;
    height: 100vh;
    font-size: 0;
    &:hover {
        .card {
            opacity: 0.3;
            filter: grayscale(100%);
            &:hover,
            &.is-active {
                opacity: 1;
                filter: none;
            }
        }
    }
}

.card {
    display: inline-block;
    vertical-align: middle;
    position: absolute;
    overflow: hidden;
    width: 100% / $nb-columns;
    height: 100% / $nb-rows;
    cursor: pointer;
    transition: all $transition-duration linear, opacity 300ms linear, filter 300ms linear;
    &.is-active {
        z-index: 1;
        top: 0 !important;
        left: 0 !important;
        width: 100%;
        height: 100%;
        opacity: 1;
        transform: rotateY(180deg);
        filter: none;
        .card-front {
            opacity: 0;
            filter: none;
        }
        .card-back,
        .card-back-wrapper {
            opacity: 1;
        }
        .card-back-wrapper {
            transition: opacity 300ms $transition-duration linear;
        }
    }
}

.card-front,
.card-back {
    width: 100%;
    height: 100%;
    transition: all 0ms $transition-duration * 0.5 linear;
}

.card-front {
    background-position: center;
    background-size: cover;
}

.card-back {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    background-color: darken(#1d1f20, 5%);
    p {
        position: absolute;
        top: 50%;
        left: 50%;
        margin: 0;
        font-size: 24px;
        color: #fff;
        transform: translate(-50%, -50%);
    }
}

.card-back-wrapper {
    position: relative;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 100ms 0ms;
    transform: rotateY(180deg);
}

@function str-repeat($string, $times) {
    $result: "";
    @for $i from 1 through $times {
        $result: $result + $string;
    }
    @return $result;
}

@for $index from 1 through $nb-cards {
    @if ($index - 1) % $nb-columns == 0 {
        .card:nth-child(#{$index}) {
            top: 100% / $nb-rows * (($index - 1) / $nb-columns);
            @if $nb-columns - 1 > 0 {
                @for $i from 1 through $nb-columns - 1 {
                    #{str-repeat("+ .card", $i)} {
                        top: 100% / $nb-rows * (($index - 1) / $nb-columns);
                    }
                }
            }
        }
    }
    .card:nth-child(#{$index}) {
        left: 100% / $nb-columns * (($index - 1) % $nb-columns);
    }
    .card:nth-child(#{$index}) .card-front {
        background-image: url(#{nth($images, $index)});
    }
}
!

JS 

              
                $('.card').on('click', function() {
    $(this).toggleClass('is-active');
});
!
999px

Console