/**
 * Block 8 — 護肝營養素翻面圖卡
 * 桌機：300px 寬、flex 橫向置中、列高 min 500px 可伸長、無捲軸
 * 手機：單欄 90%（max 300px）、高度隨內容、背面字級加大
 */

.section-nutrition {
  padding-top: clamp(28px, 4vw, 56px);
  padding-bottom: clamp(28px, 4vw, 56px);
}

.section-nutrition .container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 clamp(16px, 3vw, 24px);
}

.section-nutrition__header {
  text-align: center;
  margin-bottom: clamp(22px, 3vw, 36px);
}

.section-nutrition__eyebrow {
  display: inline-block;
  margin: 0 0 8px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: #0d9488;
}

.section-nutrition__title {
  margin: 0;
  font-family: "Noto Serif TC", "Noto Sans TC", "Microsoft JhengHei", serif;
  font-size: clamp(1.35rem, 2.4vw, 1.85rem);
  font-weight: 700;
  color: #0f172a;
  line-height: 1.35;
}

.section-nutrition__intro {
  max-width: 42rem;
  margin: clamp(18px, 2.5vw, 28px) auto 0;
  text-align: left;
}

.section-nutrition__intro p {
  margin: 0 0 1em;
  font-size: clamp(0.9375rem, 1.6vw, 1.0625rem);
  line-height: 1.75;
  color: #334155;
}

.section-nutrition__intro p:last-child {
  margin-bottom: 0;
}

.section-nutrition__hint {
  margin: clamp(14px, 2vw, 20px) 0 0;
  font-size: 0.8125rem;
  color: #64748b;
}

/* 桌機：橫向 flex、置中；手機：單欄置中 */
.nutrition-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: flex-start;
  gap: clamp(16px, 2vw, 24px);
}

.nutrition-flip {
  perspective: 1100px;
  flex: 0 0 auto;
  width: 90%;
  max-width: 300px;
  margin: 0 auto;
}

@media (min-width: 900px) {
  .nutrition-grid {
    flex-direction: row;
  }

  .nutrition-flip {
    flex: 0 0 300px;
    width: 300px;
    max-width: 300px;
    margin: 0;
  }
}

/*
 * Grid 堆疊兩面：列高 = max(正面, 背面)，可隨內容伸長，避免絕對定位無法撐高
 */
.nutrition-flip__inner {
  display: grid;
  grid-template-columns: 1fr;
  grid-template-rows: minmax(0, auto);
  width: 100%;
  transform-style: preserve-3d;
  transition: transform 0.65s cubic-bezier(0.4, 0.2, 0.2, 1);
  border-radius: 14px;
}

@media (min-width: 900px) {
  .nutrition-flip__inner {
    grid-template-rows: minmax(500px, auto);
  }
}

@media (hover: hover) and (pointer: fine) {
  .section-nutrition:not([data-touch-flip]) .nutrition-flip:hover .nutrition-flip__inner,
  .section-nutrition:not([data-touch-flip]) .nutrition-flip:focus-within .nutrition-flip__inner {
    transform: rotateY(180deg);
  }
}

.section-nutrition[data-touch-flip] .nutrition-flip.is-flipped .nutrition-flip__inner {
  transform: rotateY(180deg);
}

.nutrition-flip__face {
  grid-area: 1 / 1;
  position: relative;
  width: 100%;
  min-height: 100%;
  align-self: stretch;
  border-radius: 14px;
  overflow: hidden;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  /* 與子層一同參與 3D 合成，避免 WebKit 上絕對定位子元素穿透背面 */
  transform-style: preserve-3d;
  -webkit-transform-style: preserve-3d;
  box-shadow: 0 6px 20px rgba(15, 23, 42, 0.08);
  border: none;
}

/* 正面給予內在高度（供 grid 列高計算），避免僅有絕對定位圖片時高度為 0 */
.nutrition-flip__face--front {
  background: #e0f2fe;
  background-color: #e0f2fe;
  aspect-ratio: 3 / 4;
  min-height: 320px;
  /* 與背面微幅 Z 軸分開，修正 iOS Safari 翻面後正面圖層仍疊在背面的問題 */
  transform: rotateY(0deg) translateZ(1px);
  -webkit-transform: rotateY(0deg) translateZ(1px);
}

.nutrition-flip__face--front img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  display: block;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  transform: translateZ(0);
  -webkit-transform: translateZ(0);
}

.nutrition-flip__title-wrap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 16px 12px 18px;
  background: linear-gradient(transparent, rgba(15, 23, 42, 0.78));
  z-index: 1;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  transform: translateZ(0);
  -webkit-transform: translateZ(0);
}

.nutrition-flip__title {
  margin: 0;
  font-size: clamp(1.55rem, 4.2vw, 2.2rem);
  font-weight: 800;
  color: #fff;
  text-align: center;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  letter-spacing: 0.02em;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

/* 背面：欄向 flex；內文靠左齊行；小提醒貼底；25px 內距；禁止捲軸 */
.nutrition-flip__face--back {
  transform: rotateY(180deg) translateZ(1px);
  -webkit-transform: rotateY(180deg) translateZ(1px);
  background: #fff;
  background-color: #ffffff;
  display: flex;
  flex-direction: column;
  padding: 25px;
  overflow: hidden;
  text-align: left;
}

.nutrition-flip__back-main {
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  min-height: 0;
  width: 100%;
}

.nutrition-flip__body {
  margin: 0;
  width: 100%;
  font-size: clamp(0.875rem, 1.35vw, 0.9375rem);
  line-height: 1.65;
  color: #0f172a;
  text-align: justify;
  text-justify: inter-ideograph;
  overflow: visible;
}

.nutrition-flip__divider {
  flex-shrink: 0;
  width: 100%;
  max-width: 95%;
  margin: 12px 0 0;
  border: 0;
  border-top: 1px dashed #000;
}

.nutrition-flip__tip {
  flex-shrink: 0;
  width: 100%;
  margin-top: auto;
  padding-top: 14px;
  background: transparent;
  border: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
}

.nutrition-flip__badge {
  display: inline-block;
  margin-bottom: 10px;
  padding: 6px 18px;
  background: #ff4013;
  color: #fff;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  border-radius: 999px;
  line-height: 1.3;
  text-align: center;
}

.nutrition-flip__tip-text {
  margin: 0;
  align-self: stretch;
  width: 100%;
  font-size: clamp(0.8125rem, 1.25vw, 0.90625rem);
  line-height: 1.65;
  color: #0f172a;
  text-align: justify;
  text-justify: inter-ideograph;
  overflow: visible;
}

/* 手機：背面字級 16px、行高加大（max-width 899px 與營養素 JS 觸控邏輯區間一致） */
@media (max-width: 899px) {
  .nutrition-flip__body {
    font-size: 16px;
    line-height: 1.75;
  }

  .nutrition-flip__tip-text {
    font-size: 16px;
    line-height: 1.75;
  }

  .nutrition-flip__badge {
    font-size: 0.875rem;
  }
}

.section-nutrition[data-touch-flip] .nutrition-flip {
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

/* YouTube Shorts（Block 8 之後） */
.shorts-video-section {
  width: 100%;
  padding: 2rem 1rem;
  background-color: #f5f5f0;
}

.shorts-container {
  position: relative;
  width: 100%;
  max-width: 320px;
  margin: 0 auto;
  aspect-ratio: 9 / 16;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.shorts-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}