/**
 * 照片燈箱與圖片總覽
 *
 * @package Yafun2027
 */

/* ==========================================================================
   照片燈箱
   - 圖片區（.yf-lb-stage）可雙指縮放、雙擊放大、放大後拖曳；未放大時左右滑動切換
   - 關閉、左右鈕與底部圖說為固定 UI，不隨圖片縮放
   ========================================================================== */

.yf-zoomable {
  cursor: zoom-in;
}

.yf-lightbox-open,
.yf-lightbox-open body {
  overflow: hidden;
}

.yf-lightbox {
  position: fixed;
  inset: 0;
  z-index: 100000;
  background: rgba(10, 14, 12, 0.97);
  color: #f0ece2;
  -webkit-user-select: none;
  user-select: none;
}

.yf-lightbox[hidden] {
  display: none;
}

.yf-lb-stage {
  position: absolute;
  inset: 0;
  overflow: hidden;
  touch-action: none;
  cursor: grab;
}

.yf-lb-stage.is-dragging {
  cursor: grabbing;
}

.yf-lb-track {
  display: flex;
  height: 100%;
  will-change: transform;
}

.yf-lb-track.is-animating {
  transition: transform 0.32s cubic-bezier(0.22, 1, 0.36, 1);
}

.yf-lb-slide {
  position: relative; /* 讓圖片的 offsetLeft/Top 以所在 slide 為基準，縮放計算才正確 */
  flex: 0 0 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  overflow: hidden;
}

.yf-lb-slide img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
  transform-origin: 0 0;
  will-change: transform;
  -webkit-user-drag: none;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.yf-lb-slide img.is-animating {
  transition: transform 0.25s ease, opacity 0.3s ease;
}

/* 照片載入中：沙色圓環＋文字，載入超過 0.25 秒才出現（已快取的照片不會閃一下）；載好後照片淡入 */
.yf-lb-slide.is-loading img {
  opacity: 0;
}

.yf-lb-slide.is-loading::before,
.yf-lb-slide.is-loading::after {
  position: absolute;
  left: 50%;
  opacity: 0;
  animation: yf-lb-loading-in 0.2s ease 0.25s forwards;
  pointer-events: none;
}

.yf-lb-slide.is-loading::before {
  content: "";
  top: calc(50% - 30px);
  width: 40px;
  height: 40px;
  margin-left: -20px;
  border: 3px solid rgba(255, 255, 255, 0.15);
  border-top-color: var(--color-sand);
  border-radius: 50%;
  animation: yf-lb-loading-in 0.2s ease 0.25s forwards, yf-lb-spin 0.8s linear infinite;
}

.yf-lb-slide.is-loading::after {
  content: "照片載入中";
  top: calc(50% + 22px);
  transform: translateX(-50%);
  color: rgba(255, 255, 255, 0.75);
  font-size: 1.5rem;
  letter-spacing: 0.15em;
  white-space: nowrap;
}

@keyframes yf-lb-loading-in {
  to {
    opacity: 1;
  }
}

@keyframes yf-lb-spin {
  to {
    transform: rotate(360deg);
  }
}

/* 固定 UI：頂端計數與關閉、兩側切換、底部圖說 */
.yf-lb-top {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: calc(1rem + env(safe-area-inset-top, 0px)) max(1rem, env(safe-area-inset-right, 0px)) 1rem max(1.6rem, env(safe-area-inset-left, 0px));
  background: linear-gradient(to bottom, rgba(10, 14, 12, 0.7), rgba(10, 14, 12, 0));
  pointer-events: none;
}

.yf-lb-count {
  font-family: var(--font-pen);
  font-size: 2rem;
  font-weight: 500;
  color: #f1e3c4;
  font-variant-numeric: tabular-nums;
}

.yf-lb-top {
  gap: 1rem;
}

/* 計數旁的「最後一張」標籤 */
.yf-lb-end-tag {
  margin-right: auto;
  padding: 0.2em 0.9em;
  border-radius: 999px;
  background: var(--color-sand);
  color: var(--forest-900);
  font-size: 1.4rem;
  font-weight: 600;
  letter-spacing: 0.08em;
}

.yf-lb-end-tag[hidden] {
  display: none;
}

.yf-lightbox button {
  pointer-events: auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 4.8rem;
  height: 4.8rem;
  padding: 0;
  border: 1px solid rgba(240, 236, 226, 0.3);
  border-radius: 50%;
  background: rgba(10, 14, 12, 0.45);
  color: #f0ece2;
  font-family: Arial, sans-serif;
  font-size: 2.6rem;
  line-height: 1;
  cursor: pointer;
  transition: background-color 0.2s, color 0.2s;
}

.yf-lightbox button:hover,
.yf-lightbox button:focus-visible {
  background: #f0ece2;
  color: #17201b;
  outline: none;
}

.yf-lb-prev,
.yf-lb-next {
  position: absolute;
  top: 50%;
  z-index: 2;
  transform: translateY(-50%);
}

.yf-lb-prev { left: max(1.2rem, env(safe-area-inset-left, 0px)); }
.yf-lb-next { right: max(1.2rem, env(safe-area-inset-right, 0px)); }

/* 到頭／到尾的箭頭變淡，但仍可按（按了會出現提示） */
.yf-lightbox .yf-lb-prev.is-edge,
.yf-lightbox .yf-lb-next.is-edge {
  opacity: 0.3;
}

/* 到頭／到尾提示 */
.yf-lb-edge {
  position: absolute;
  left: 50%;
  bottom: calc(9rem + env(safe-area-inset-bottom, 0px));
  z-index: 3;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.2rem;
  width: max-content;
  max-width: calc(100% - 3.2rem);
  padding: 2rem 2.4rem;
  border-radius: 14px;
  background: rgba(10, 14, 12, 0.88);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
  transform: translateX(-50%);
  animation: yf-lb-edge-in 0.25s ease-out;
}

.yf-lb-edge[hidden] {
  display: none;
}

.yf-lb-edge-text {
  margin: 0;
  padding: 0;
  font-size: 1.8rem;
  color: #f1e3c4;
}

.yf-lb-edge-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
}

.yf-lightbox .yf-lb-edge-btn {
  width: auto;
  min-height: 4.4rem;
  height: auto;
  padding: 0 2rem;
  border-radius: 999px;
  border-color: var(--color-sand);
  background: var(--color-sand);
  color: var(--forest-900);
  font-family: var(--font-serif);
  font-size: 1.6rem;
}

.yf-lightbox .yf-lb-edge-btn.is-ghost {
  background: transparent;
  color: #f0ece2;
}

@keyframes yf-lb-edge-in {
  from { opacity: 0; transform: translate(-50%, 8px); }
  to { opacity: 1; transform: translate(-50%, 0); }
}

@media (prefers-reduced-motion: reduce) {
  .yf-lb-edge {
    animation: none;
  }
}

.yf-lightbox.is-single .yf-lb-prev,
.yf-lightbox.is-single .yf-lb-next,
.yf-lightbox.is-single .yf-lb-count {
  visibility: hidden;
}

.yf-lb-caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2;
  max-height: 30vh;
  overflow-y: auto;
  padding: 3.2rem max(2rem, env(safe-area-inset-right, 0px)) calc(1.6rem + env(safe-area-inset-bottom, 0px)) max(2rem, env(safe-area-inset-left, 0px));
  background: linear-gradient(to top, rgba(10, 14, 12, 0.88) 40%, rgba(10, 14, 12, 0));
  font-size: 1.5rem;
  line-height: 1.7;
  text-align: center;
  color: #e8e4d8;
}

.yf-lb-caption:empty {
  display: none;
}

/* 放大檢視時淡出 UI，讓畫面專注在圖片 */
.yf-lightbox.is-zoomed .yf-lb-prev,
.yf-lightbox.is-zoomed .yf-lb-next,
/* 圖說下方的版權字樣 */
.yf-lb-credit {
  display: block;
  margin-top: 0.4rem;
  font-size: 1.25rem;
  letter-spacing: 0.06em;
  color: rgba(232, 228, 216, 0.6);
}

.yf-lightbox.is-zoomed .yf-lb-caption {
  opacity: 0;
  pointer-events: none;
}

.yf-lb-prev,
.yf-lb-next,
.yf-lb-caption {
  transition: opacity 0.2s;
}

/* 觸控裝置：滑動即可切換，隱藏左右鈕 */
@media (hover: none) and (pointer: coarse) {
  .yf-lb-prev,
  .yf-lb-next {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  /* 載入中：不旋轉，只顯示圓環與文字 */
  .yf-lb-slide.is-loading::before {
    animation: yf-lb-loading-in 0.2s ease 0.25s forwards;
  }

  .yf-lb-track.is-animating,
  .yf-lb-slide img.is-animating {
    transition: none;
  }
}
/* ==========================================================================
   燈箱：圖片總覽（教學時快速找圖）
   ========================================================================== */

.yf-lb-actions {
  display: inline-flex;
  align-items: center;
  gap: 1rem;
  pointer-events: auto;
}

.yf-lightbox.is-single .yf-lb-grid-toggle {
  display: none;
}

.yf-lightbox .yf-lb-grid-toggle[aria-pressed="true"] {
  background: var(--color-sand);
  border-color: var(--color-sand);
  color: var(--forest-900);
}

/* 總覽開啟時隱藏大圖檢視的元件 */
.yf-lightbox.is-grid .yf-lb-stage,
.yf-lightbox.is-grid .yf-lb-prev,
.yf-lightbox.is-grid .yf-lb-next,
.yf-lightbox.is-grid .yf-lb-caption {
  display: none;
}

.yf-lb-grid {
  position: absolute;
  inset: 0;
  z-index: 1;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  grid-auto-rows: max-content; /* 列高依縮圖決定，圖多時往下捲動，不壓扁塞進一個畫面 */
  align-content: start;
  gap: 1.6rem;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: calc(8.4rem + env(safe-area-inset-top, 0px)) max(3rem, env(safe-area-inset-right, 0px)) calc(4rem + env(safe-area-inset-bottom, 0px)) max(3rem, env(safe-area-inset-left, 0px));
  -webkit-user-select: none;
  user-select: none;
}

.yf-lb-grid[hidden] {
  display: none;
}

.yf-lightbox .yf-lb-grid-item {
  position: relative;
  display: flex;
  flex-direction: column;
  width: auto;
  height: auto;
  padding: 0;
  overflow: hidden;
  border: 2px solid transparent;
  border-radius: 8px;
  background: rgba(240, 236, 226, 0.06);
  color: var(--on-dark);
  font-family: var(--font-serif);
  text-align: left;
  cursor: pointer;
  transition: border-color 0.2s, transform 0.2s, background-color 0.2s;
}

.yf-lightbox .yf-lb-grid-item:hover,
.yf-lightbox .yf-lb-grid-item:focus-visible {
  border-color: rgba(240, 236, 226, 0.6);
  background: rgba(240, 236, 226, 0.1);
  color: var(--on-dark);
  transform: translateY(-2px);
  outline: none;
}

.yf-lightbox .yf-lb-grid-item.is-current {
  border-color: var(--color-sand);
}

.yf-lb-grid-item img {
  display: block;
  width: 100%;
  flex: 0 0 auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  pointer-events: none;
}

.yf-lb-grid-num {
  position: absolute;
  top: 0.8rem;
  left: 0.8rem;
  min-width: 2.8rem;
  padding: 0.1em 0.6em;
  border-radius: 999px;
  background: rgba(10, 14, 12, 0.7);
  font-family: var(--font-pen);
  font-size: 1.6rem;
  font-weight: 500;
  line-height: 1.4;
  text-align: center;
  color: #f1e3c4;
}

.yf-lb-grid-item.is-current .yf-lb-grid-num {
  background: var(--color-sand);
  color: var(--forest-900);
}

/* 縮圖下的圖說：教學時用來辨認是哪一張 */
.yf-lb-grid-cap {
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
  padding: 0.8rem 1rem 1rem;
  font-size: 1.35rem;
  line-height: 1.6;
  color: var(--on-dark-muted);
}

@media (max-width: 960px) {
  .yf-lb-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1.2rem;
    padding-left: max(1.6rem, env(safe-area-inset-left, 0px));
    padding-right: max(1.6rem, env(safe-area-inset-right, 0px));
  }
}

@media (max-width: 600px) {
  .yf-lb-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.8rem;
    padding-top: calc(7.2rem + env(safe-area-inset-top, 0px));
  }

  .yf-lb-grid-cap {
    display: none; /* 手機縮圖較小，只顯示編號 */
  }

  .yf-lb-grid-num {
    top: 0.4rem;
    left: 0.4rem;
    font-size: 1.4rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .yf-lightbox .yf-lb-grid-item {
    transition: none;
  }

  .yf-lightbox .yf-lb-grid-item:hover {
    transform: none;
  }
}