.masonry-grid * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
.masonry-grid {
    padding: 0;
    margin: 0;
    list-style: none;
    column-count: 4;
    column-gap: 1em;
    margin: 1em;
}
.masonry-grid li {
    break-inside: avoid;
    margin-bottom: 1em;
    background: #eee;
    overflow: hidden;
    position: relative;
}
.masonry-grid li::before {
    content: "Loading...";
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #666;
    z-index: 1;
}
.masonry-grid li.loaded::before {
    display: none;
}
.masonry-grid img {
    width: 100%;
    display: block;
    opacity: 0;
    transition: opacity 0.3s ease;
}
.masonry-grid img.visible {
    opacity: 1;
}
.masonry-grid img:hover {
    -moz-filter: brightness(70%);
    -webkit-filter: brightness(70%);
    filter: brightness(70%);
    transition: ease-in-out 0.25s;
}
@media (max-width: 1200px) {
    .masonry-grid {
        column-count: 3;
    }
}
@media (max-width: 600px) {
    .masonry-grid {
        column-count: 2;
    }
}