/* ==========================================================================
   相册瀑布流矩阵（gallery mosaic）
   适配 Butterfly 5.3.5：页面正文位于 #article-container 内，
   由 tools/sync_gallery.py 生成
     <div class="mosaic-gallery" data-album="...">
       <a class="mosaic-item" href="原图" data-fancybox="..."><img src="缩略图"></a>
     </div>
   点击由主题的 Fancybox 接管（utils.js 对已在 <a> 内的图片只做 Fancybox.bind）。
   ========================================================================== */

.mosaic-gallery {
  column-count: 3;
  column-gap: 12px;
  column-fill: balance;
  margin: 4px 0 28px;
  padding: 0;
  line-height: 0;
}

.mosaic-gallery .mosaic-item {
  display: block;
  margin: 0 0 12px;
  padding: 0;
  border-radius: 8px;
  overflow: hidden;
  background: rgba(127, 127, 127, 0.08);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.08);
  line-height: 0;
  text-decoration: none !important;
  /* 多列布局内禁止条目被拆到两列 */
  break-inside: avoid;
  -webkit-column-break-inside: avoid;
  page-break-inside: avoid;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.mosaic-gallery .mosaic-item:hover,
.mosaic-gallery .mosaic-item:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.16);
  text-decoration: none !important;
}

/* 覆盖主题 #article-container（.container）对 img 的默认 margin / 圆角 / 过渡 */
#article-container .mosaic-gallery .mosaic-item img,
.mosaic-gallery .mosaic-item img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  margin: 0;
  padding: 0;
  border: 0;
  border-radius: 0;
  box-shadow: none;
  transform-origin: center center;
  transition: transform 0.35s ease, filter 0.35s ease;
}

.mosaic-gallery .mosaic-item:hover img,
.mosaic-gallery .mosaic-item:focus-visible img {
  transform: scale(1.04);
  filter: brightness(1.06);
}

/* ==========================================================================
   深色模式（Butterfly 通过 [data-theme='dark'] 切换 CSS 变量）
   ========================================================================== */

[data-theme="dark"] .mosaic-gallery .mosaic-item {
  background: rgba(255, 255, 255, 0.06);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.45);
}

[data-theme="dark"] .mosaic-gallery .mosaic-item:hover,
[data-theme="dark"] .mosaic-gallery .mosaic-item:focus-visible {
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.6);
}

[data-theme="dark"] .mosaic-gallery .mosaic-item:hover img,
[data-theme="dark"] .mosaic-gallery .mosaic-item:focus-visible img {
  filter: brightness(1.12);
}

/* ==========================================================================
   响应式列数：≤900px 两列，≤600px 单列
   ========================================================================== */

@media screen and (max-width: 900px) {
  .mosaic-gallery {
    column-count: 2;
  }
}

@media screen and (max-width: 600px) {
  .mosaic-gallery {
    column-count: 1;
    column-gap: 0;
  }

  .mosaic-gallery .mosaic-item {
    margin-bottom: 10px;
    border-radius: 6px;
  }
}

/* 极老浏览器不支持多列时退回 flex 网格，保证仍然能看 */
@supports not (column-count: 3) {
  .mosaic-gallery {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
  }

  .mosaic-gallery .mosaic-item {
    flex: 1 1 30%;
    margin: 0;
  }
}

/* ==========================================================================
   点击看大图：内置兜底灯箱（Fancybox 不可用时启用）
   由 source/js/gallery-mosaic.js 动态创建 .mosaic-lightbox 元素
   ========================================================================== */

body.mosaic-lb-open {
  overflow: hidden;
}

.mosaic-lightbox {
  position: fixed;
  inset: 0;
  z-index: 10060;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 28px;
  background: rgba(8, 10, 14, 0.9);
  -webkit-backdrop-filter: blur(2px);
  backdrop-filter: blur(2px);
}

.mosaic-lightbox.is-open {
  display: flex;
}

.mosaic-lightbox .mosaic-lb-figure {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  max-width: 92vw;
  margin: 0;
  line-height: 0;
}

.mosaic-lightbox .mosaic-lb-img {
  display: block;
  max-width: 92vw;
  max-height: 86vh;
  width: auto;
  height: auto;
  margin: 0;
  border-radius: 6px;
  box-shadow: 0 12px 48px rgba(0, 0, 0, 0.55);
  object-fit: contain;
}

.mosaic-lightbox .mosaic-lb-caption {
  margin-top: 12px;
  color: rgba(255, 255, 255, 0.82);
  font-size: 13px;
  line-height: 1.5;
  text-align: center;
}

.mosaic-lightbox button {
  position: absolute;
  top: 50%;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.14);
  color: #fff;
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  transform: translateY(-50%);
  transition: background-color 0.2s, color 0.2s;
}

.mosaic-lightbox button:hover {
  background: rgba(73, 177, 245, 0.85);
  color: #fff;
}

.mosaic-lightbox .mosaic-lb-close {
  top: 18px;
  right: 18px;
  width: 38px;
  height: 38px;
  font-size: 22px;
  transform: none;
}

.mosaic-lightbox .mosaic-lb-prev {
  left: 18px;
}

.mosaic-lightbox .mosaic-lb-next {
  right: 18px;
}

@media screen and (max-width: 600px) {
  .mosaic-lightbox {
    padding: 12px;
  }

  .mosaic-lightbox .mosaic-lb-prev,
  .mosaic-lightbox .mosaic-lb-next {
    width: 34px;
    height: 34px;
    font-size: 14px;
  }

  .mosaic-lightbox .mosaic-lb-prev {
    left: 8px;
  }

  .mosaic-lightbox .mosaic-lb-next {
    right: 8px;
  }

  .mosaic-lightbox .mosaic-lb-img {
    max-width: 94vw;
    max-height: 80vh;
  }
}