.masonry { /* CONTAINER */
    column-count: 4;
    column-gap: 1em;
}

.item_photo { /* Masonry bricks or child elements */
    background-color: #eee;
    display: inline-block;
    margin: 0 0 1em;
    width: 100%;
}


.wrapper_galerie {
    width: 95%;
    margin: 3em auto;
}

.masonry {
    margin: 1.5em 0;
    padding: 0;
    -moz-column-gap: 1.5em;
    -webkit-column-gap: 1.5em;
    column-gap: 1.5em;
    font-size: .85em;
}

.item_photo {
    display: inline-block;
    background: #fff;
    padding: 1em;
    margin: 0 0 1.5em;
    width: 100%;
	-webkit-transition:1s ease all;
    box-sizing: border-box;
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;
    box-shadow: 2px 2px 4px 0 #ccc;
}
.item_photo img {
	max-width:100%;
}

@media only screen and (min-width: 400px) {
    .masonry {
        -moz-column-count: 2;
        -webkit-column-count: 2;
        column-count: 2;
    }
}

@media only screen and (min-width: 700px) {
    .masonry {
        -moz-column-count: 3;
        -webkit-column-count: 3;
        column-count: 3;
    }
}

@media only screen and (min-width: 900px) {
    .masonry {
        -moz-column-count: 4;
        -webkit-column-count: 4;
        column-count: 4;
    }
}

@media only screen and (min-width: 1100px) {
    .masonry {
        -moz-column-count: 5;
        -webkit-column-count: 5;
        column-count: 5;
    }
}

@media only screen and (min-width: 1280px) {
    .wrapper_galerie {
        width: 1200px;
    }
}