.slider.image-comparison {
    --slider-position: 50%;
    box-sizing: border-box;
    position: relative;
    isolation: isolate;
    width: 80%;
    height: auto;
    aspect-ratio: 4 / 3;
    padding: 0;
    margin: 1em auto;
    overflow: hidden;
    border-radius: 0.5rem;
}

@media screen and (max-width: 660px) {
    .slider.image-comparison {
        width: 95%;
    }
}

.image-comparison > .slider-layer {
    position: absolute;
    inset: 0;
}

/* 裁剪整个图层，灯箱链接和淡入背景也随图片一起裁剪。 */
.image-comparison > .slider-left {
    clip-path: inset(0 calc(100% - var(--slider-position)) 0 0);
}

.image-comparison > .slider-right {
    clip-path: inset(0 0 0 var(--slider-position));
}

/* 兼容裸图片，以及博客生成的 a/span/淡入包装层。 */
.image-comparison .slider-layer :is(a, span, img) {
    box-sizing: border-box;
    position: static;
    display: block;
    width: 100%;
    height: 100%;
    max-width: none;
    max-height: none;
    margin: 0;
    padding: 0;
    border-radius: 0;
}

.image-comparison .slider-layer img {
    object-fit: cover;
    clip-path: none;
    user-select: none;
    -webkit-user-drag: none;
}

.image-comparison > .mask {
    position: absolute;
    z-index: 2;
    top: 0;
    left: var(--slider-position);
    width: 28px;
    height: 100%;
    transform: translateX(-50%);
    background: transparent;
    cursor: ew-resize;
    touch-action: none;
    user-select: none;
}

.image-comparison > .mask::before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    left: calc(50% - 2px);
    width: 4px;
    background: rgba(0, 0, 0, 0.66);
}

.image-comparison > .mask:focus-visible {
    outline: 2px solid #38bdf8;
    outline-offset: -2px;
}