:root {
    --lig-gap: 4px;
    --lig-radius: 0px;
}

.image-grid {
    box-sizing: border-box;
    display: grid;
    width: 100%;
    max-width: 100%;
    gap: var(--lig-gap);
    padding: 0;
    overflow: hidden;
    line-height: 0;
}

.image-grid *,
.image-grid *::before,
.image-grid *::after {
    box-sizing: border-box;
}

.image-grid .grid-item {
    display: block;
    position: relative;
    min-width: 0;
    min-height: 0;
    margin: 0 !important;
    padding: 0 !important;
    overflow: hidden;
    border-radius: var(--lig-radius);
    line-height: 0;
}

.image-grid .grid-item > img,
.image-grid .grid-item > a,
.image-grid .grid-item > a > img,
.image-grid .grid-item > iframe {
    margin: 0 !important;
    padding: 0 !important;
    border: 0 !important;
    max-width: none !important;
}

.image-grid .grid-item > a {
    display: block;
    width: 100%;
    height: 100%;
    line-height: 0;
}

.image-grid .grid-item img {
    display: block !important;
    width: 100% !important;
    height: 100% !important;
    object-fit: cover;
    border-radius: inherit;
}

.image-grid .grid-item img[data-lig-lightbox-ready] {
    cursor: zoom-in;
}

.lig-lightbox {
    position: fixed;
    z-index: 2147483647;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 48px 24px 24px;
    /**background: rgba(0, 0, 0, 0.88);**/
    background: rgb(197 197 197 / 88%);
    opacity: 0;
    visibility: hidden;
    transition: opacity 160ms ease, visibility 160ms ease;
}

.lig-lightbox.is-open {
    opacity: 1;
    visibility: visible;
}

.lig-lightbox__image {
    display: block;
    width: auto;
    height: auto;
    max-width: 100%;
    max-height: calc(100vh - 72px);
    object-fit: contain;
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.45);
}

.lig-lightbox__close {
    position: absolute;
    top: 8px;
    right: 12px;
    width: 40px;
    height: 40px;
    padding: 0;
    border: 0;
    background: transparent;
    color: #fff;
    font: 36px/40px Arial, sans-serif;
    cursor: pointer;
}

body.lig-lightbox-open {
    overflow: hidden;
}

.image-grid .grid-item iframe {
    display: block;
    width: 100%;
    height: 100%;
}

/* 横排：典型为两张横图并排。 */
.image-grid.landscape {
    grid-template-columns: repeat(2, minmax(0, 1fr));
/*     aspect-ratio: 2 / 1; */
}

/* 竖排：典型为三张竖图横向排列。 */
.image-grid.portrait {
    grid-template-columns: repeat(3, minmax(0, 1fr));
/*     aspect-ratio: 3 / 2; */
}

/*
 * 横竖混排：
 * r73 = 左 70% / 右 30%
 * r37 = 左 30% / 右 70%
 * r64 = 左 60% / 右 40%
 * r46 = 左 40% / 右 60%
 */
.image-grid.r73 {
    grid-template-columns: minmax(0, 7fr) minmax(0, 3fr);
    aspect-ratio: 16 / 9;
}

.image-grid.r37 {
    grid-template-columns: minmax(0, 3fr) minmax(0, 7fr);
    aspect-ratio: 16 / 9;
}

.image-grid.r64 {
    grid-template-columns: minmax(0, 6fr) minmax(0, 4fr);
    aspect-ratio: 16 / 9;
}

.image-grid.r46 {
    grid-template-columns: minmax(0, 4fr) minmax(0, 6fr);
    aspect-ratio: 16 / 9;
}

/* 多于预期图片数量时仍能自然排版，不溢出正文。 */
.image-grid.landscape .grid-item:nth-child(n+3),
.image-grid.r73 .grid-item:nth-child(n+3),
.image-grid.r37 .grid-item:nth-child(n+3),
.image-grid.r64 .grid-item:nth-child(n+3),
.image-grid.r46 .grid-item:nth-child(n+3) {
    aspect-ratio: 16 / 10;
}

.image-grid.portrait .grid-item:nth-child(n+4) {
    aspect-ratio: 2 / 3;
}

.image-grid.r73 .grid-item .single-photo,
.image-grid.r37 .grid-item .single-photo,
.image-grid.r64 .grid-item .single-photo,
.image-grid.r46 .grid-item .single-photo {
    height: 100%;
}


@media (max-width: 640px) {
    .image-grid {
        gap: min(var(--lig-gap), 4px);
    }

    .image-grid.portrait {
/*         aspect-ratio: 3 / 2.2; */
    }

    .image-grid.r73,
    .image-grid.r37,
    .image-grid.r64,
    .image-grid.r46 {
        aspect-ratio: 4 / 3;
    }
}