.gallery {
    -webkit-column-count: 3;
    -moz-column-count: 3;
    column-count: 3;
    -webkit-column-gap: 10px;
    -moz-column-gap: 10px;
    column-gap: 10px;
    margin-top: 10px;
    overflow: hidden;
}

.gallery img {
        width: 100%;
        height: auto;
        transition: 500ms;
        margin-bottom: 10px;
        opacity: 0.8;
        page-break-inside: avoid; /* For Firefox. */
        -webkit-column-break-inside: avoid; /* For Chrome & friends. */
        break-inside: avoid; /* For standard browsers like IE. :-) */
 }
.gallery img:hover {opacity: 1;}

.modal-img, .model-vid {
    width: 100%;
    height: auto;
}

.modal-body {
    padding: 0px;
}

.modal-dialog {
    text-align: center;
    vertical-align: middle;
    display: block;
    top: 10%;
}

.modal-content {
    border: none;
}

@media screen and (max-width: 767px) {
.gallery {
        -webkit-column-count: 3;
        -moz-column-count: 3;
        column-count: 3;
}

.gallery div {
            margin: 0;
            width: 200px;
}
}

@media screen and (max-width: 479px) {
    .gallery {
        -webkit-column-count: 1;
        -moz-column-count: 1;
        column-count: 1;
}
        .gallery div {
            margin: 0;
            width: 200px;
        }
}