.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: 2;
        -moz-column-count: 2;
        column-count: 2;
    }
    .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;
    }
}