/* ===========================================================
 * 便携 DR 视频方案 · 投影展示页样式（浅色 · 医疗科技风）
 * 设计基准：16:9 (1920 x 1080) 自适应缩放
 * 深色版备份：style-dark.css
 * ========================================================= */

:root {
  /* 背景：温润浅蓝紫 */
  --bg-0: #f5f7ff;
  --bg-1: #eef2ff;
  --bg-2: #e8ecfb;

  /* 文字：深蓝灰主色 */
  --ink-0: #1a2240;
  --ink-1: #4b5a7a;
  --ink-2: #8a96b3;

  /* 线条与卡片 */
  --line: rgba(91, 110, 247, 0.12);
  --line-strong: rgba(91, 110, 247, 0.28);
  --card-bg: rgba(255, 255, 255, 0.78);
  --card-border: rgba(91, 110, 247, 0.18);
  --card-hover: rgba(91, 110, 247, 0.55);

  /* 主色：医疗蓝紫 */
  --cyan: #5fb8ff;
  --cyan-soft: #4f8df0;
  --blue: #4f6ef7;
  --black: #000000;
  --teal: #00bfa6;
  --purple: #8b6cff;
  --accent-grad: linear-gradient(135deg, #5fb8ff 0%, #4f6ef7 55%, #8b6cff 100%);

  /* 阴影：柔和、明亮 */
  --shadow-1: 0 10px 30px rgba(91, 110, 247, 0.12);
  --shadow-2: 0 18px 50px rgba(91, 110, 247, 0.20);
  --shadow-3: 0 5px 20px rgba(91, 110, 247, 0.20);

  --radius: 14px;
  --radius-lg: 22px;
  --font-zh: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  --font-en: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body {
  width: 100%; height: 100%;
  overflow: hidden;
  background: var(--bg-0);
  color: var(--ink-0);
  font-family: var(--font-zh), var(--font-en);
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  user-select: none;
}
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
svg { width: 100%; height: 100%; display: block; }

/* ---------- 科技感背景（浅色） ---------- */
.bg-tech {
  position: fixed; inset: 0; z-index: 0; overflow: hidden;
  background:
    radial-gradient(1200px 800px at 20% 10%, #eaf0ff 0%, transparent 60%),
    radial-gradient(1000px 700px at 85% 90%, #f1ecff 0%, transparent 55%),
    linear-gradient(180deg, #f7f9ff 0%, #eef1fb 100%);
}
.bg-grid {
  position: absolute; inset: -2px;
  background-image:
    linear-gradient(rgba(91, 110, 247, 0.10) 1px, transparent 1px),
    linear-gradient(90deg, rgba(91, 110, 247, 0.10) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at center, #000 40%, transparent 90%);
  animation: gridShift 24s linear infinite;
}
@keyframes gridShift {
  0% { background-position: 0 0, 0 0; }
  100% { background-position: 48px 48px, 48px 48px; }
}
.bg-glow {
  position: absolute; border-radius: 50%; filter: blur(90px); opacity: 0.55;
  mix-blend-mode: multiply;
}
.glow-1 { width: 600px; height: 600px; background: #c9d6ff; top: -120px; left: -120px; animation: glowFloat 18s ease-in-out infinite; }
.glow-2 { width: 520px; height: 520px; background: #d6cfff; bottom: -160px; right: -100px; animation: glowFloat 22s ease-in-out infinite reverse; }
.glow-3 { width: 380px; height: 380px; background: #cfeaff; top: 40%; left: 60%; animation: glowFloat 26s ease-in-out infinite; }
@keyframes glowFloat {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(60px, -40px) scale(1.15); }
}
.bg-scan {
  position: absolute; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, transparent, rgba(91, 110, 247, 0.45), transparent);
  filter: blur(1px);
  animation: scanMove 8s linear infinite;
}
@keyframes scanMove {
  0% { top: -2%; opacity: 0; }
  20% { opacity: 1; }
  80% { opacity: 1; }
  100% { top: 102%; opacity: 0; }
}
.bg-particles { position: absolute; inset: 0; }
.bg-particles .p {
  position: absolute; width: 3px; height: 3px; border-radius: 50%;
  background: var(--blue); box-shadow: 0 0 10px rgba(91, 110, 247, 0.6);
  opacity: 0.55;
  animation: pFloat linear infinite;
}
@keyframes pFloat {
  0% { transform: translateY(110vh) scale(0.6); opacity: 0; }
  10% { opacity: 0.7; }
  90% { opacity: 0.7; }
  100% { transform: translateY(-10vh) scale(1.2); opacity: 0; }
}

/* ---------- 顶部品牌栏 ---------- */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; height: 56px; z-index: 20;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 36px;
  background: linear-gradient(180deg, rgba(245, 247, 255, 0.9), rgba(245, 247, 255, 0));
  pointer-events: none;
}
.brand { display: flex; align-items: center; gap: 12px; font-family: var(--font-en); letter-spacing: 2px; }
.brand-dot { width: 10px; height: 10px; border-radius: 50%; background: var(--blue); box-shadow: 0 0 12px rgba(91,110,247,0.6); animation: pulse 2s ease-in-out infinite; }
.brand-name { font-weight: 700; font-size: 15px; color: var(--ink-0); }
.brand-sub { font-size: 12px; color: var(--ink-2); }
.meta { font-family: var(--font-en); font-size: 13px; color: var(--ink-1); letter-spacing: 1px; }
.meta-sep { color: var(--ink-2); margin: 0 8px; }
@keyframes pulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 12px rgba(91,110,247,0.6); }
  50% { opacity: 0.5; box-shadow: 0 0 4px rgba(91,110,247,0.3); }
}

/* ---------- 舞台 ---------- */
.stage {
  position: relative; z-index: 5;
  width: 100vw; height: 100vh;
  display: flex; align-items: center; justify-content: center;
  padding: 72px 64px 72px;
}

.slide {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  padding: 72px 64px 80px;
  opacity: 0; pointer-events: none;
  transform: translateX(40px);
  transition: opacity 0.55s ease, transform 0.55s cubic-bezier(.2,.7,.2,1);
}
.slide.active { opacity: 1; pointer-events: auto; transform: translateX(0); }
.slide.leaving { transform: translateX(-40px); }

.slide-inner {
  width: 100%; height: 100%; max-width: 1720px;
  display: grid; grid-template-rows: auto 1fr;
  gap: 22px;
}

/* 页眉：标题区 */
.slide-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 24px; }
.slide-title-wrap { min-width: 0; }
.slide-kicker {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-en); font-size: 12px; letter-spacing: 3px;
  color: var(--blue); text-transform: uppercase;
  padding: 4px 10px; border: 1px solid var(--line-strong); border-radius: 999px;
  background: rgba(91, 110, 247, 0.06);
}
.slide-kicker::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--blue); box-shadow: 0 0 8px rgba(91,110,247,0.6); }
.slide-title {
  margin-top: 12px; font-size: 38px; font-weight: 700; letter-spacing: 1px;
  background: linear-gradient(135deg, #1a2240 0%, #4f6ef7 60%, #8b6cff 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  line-height: 1.2;
}
.slide-subtitle { margin-top: 8px; font-size: 16px; color: var(--ink-1); line-height: 1.6; max-width: 920px; }

.slide-head-actions { display: flex; gap: 10px; align-items: center; flex-shrink: 0; }
.more-btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 18px; border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(255, 255, 255, 0.8);
  font-size: 13px; color: var(--ink-0); letter-spacing: 1px;
  transition: all 0.25s ease;
  box-shadow: 0 4px 14px rgba(91, 110, 247, 0.08);
}
.more-btn:hover { border-color: var(--blue); background: rgba(91,110,247,0.08); box-shadow: 0 6px 20px rgba(91, 110, 247, 0.25); }
.more-btn .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--blue); box-shadow: 0 0 8px rgba(91,110,247,0.6); }

/* 媒体区 */
.slide-media { position: relative; width: 100%; height: 100%; min-height: 0; }

.media-1 { display: grid; grid-template-columns: 1fr; gap: 18px; height: 100%; }
.media-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; height: 100%; }
.media-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; height: 100%; }
.media-4 { display: grid; grid-template-columns: repeat(2, 1fr); grid-template-rows: repeat(2, 1fr); gap: 18px; height: 100%; }
.media-9 { display: grid; grid-template-columns: repeat(3, 1fr); grid-template-rows: repeat(3, 1fr); gap: 14px; height: 100%; }

/* feature-2：左右两个大面板；每个面板内左侧竖图大卡 + 右侧 1 列子卡 */
.media-feature-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  height: 100%;
}
.feature-panel {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  gap: 14px;
  min-height: 0;
  min-width: 0;
}
.feature-panel .fp-main {
  min-height: 0; min-width: 0;
  /* 主区域也可纵向滚动，隐藏滚动条 */
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: none;
  -ms-overflow-style: none;
}
.feature-panel .fp-main::-webkit-scrollbar { width: 0; height: 0; display: none; }
/* 主区域卡片：默认填满高度；若内部图片超出则随卡片一起滚动 */
.feature-panel .fp-main .media-card {
  min-height: 100%;
  width: 100%;
  height: auto;
}
.feature-panel .fp-list {
  display: flex; flex-direction: column; gap: 12px;
  min-height: 0; min-width: 0;
  /* 子卡片超过 3 个时纵向滚动，隐藏滚动条 */
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: none;          /* Firefox */
  -ms-overflow-style: none;        /* IE/Edge legacy */
}
.feature-panel .fp-list::-webkit-scrollbar { width: 0; height: 0; display: none; }
/* 固定每张子卡的高度，默认一列可见 5 张，超过后纵向滚动 */
.feature-panel .fp-list .media-card {
  flex: 0 0 calc((100% - 48px) / 5);  /* 5 张可视，gap 12px × 4 = 48px */
  min-height: 0;
}

/* 媒体卡片 */
.media-card {
  position: relative; overflow: hidden; border-radius: var(--radius);
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  box-shadow: var(--shadow-1);
  cursor: pointer;
  transition: transform 0.4s cubic-bezier(.2,.7,.2,1), border-color 0.3s, box-shadow 0.3s, flex 0.4s;
  backdrop-filter: blur(6px);
}
.media-card::before {
  content: ""; position: absolute; inset: 0; z-index: 2;
  background: linear-gradient(180deg, transparent 55%, rgba(106, 129, 219, 0.35) 100%);
  pointer-events: none;
}
.media-card::after {
  content: ""; position: absolute; inset: 0; z-index: 3;
  border-radius: var(--radius);
  border: 1px solid transparent;
  pointer-events: none;
  transition: border-color 0.3s, box-shadow 0.3s;
}
.media-card:hover { border-color: var(--card-hover); transform: translateY(-4px); box-shadow: var(--shadow-2); }
.media-card:hover::after { border-color: var(--blue); box-shadow: inset 0 0 30px rgba(91, 110, 247, 0.15); }

.media-card img,
.media-card video {
  width: 100%; height: 100%; object-fit: cover; display: block;
  transition: transform 0.6s ease;
}
.media-card:hover img,
.media-card:hover video { transform: scale(1.04); }

.media-card .mc-label {
  position: absolute; left: 16px; right: 16px; bottom: 14px; z-index: 4;
  display: flex; align-items: center; justify-content: space-between; gap: 10px;
}
.media-card .mc-title { font-size: 14px; font-weight: 600; color: #fff; letter-spacing: 0.5px; text-shadow: 0 1px 4px rgba(0,0,0,0.35); }
.media-card .mc-sub { font-size: 11px; color: rgba(255,255,255,0.88); margin-top: 2px; text-shadow: 0 1px 3px rgba(0,0,0,0.3); }
.media-card .mc-badge {
  position: absolute; top: 10px; right: 10px; z-index: 4;
  font-size: 10px; padding: 3px 8px; border-radius: 999px;
  background: rgba(0, 0, 0, 0.92); color: rgba(255, 255, 255, 0.92);
  border: 1px solid rgba(91, 110, 247, 0.35); letter-spacing: 1px;
  font-weight: 600;
  box-shadow: 0 2px 6px rgba(91, 110, 247, 0.18);
}

/* 视频播放按钮 */
.media-card .mc-play {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
  z-index: 4;
  width: 64px; height: 64px; border-radius: 50%;
  background: rgba(255, 255, 255, 0.15); backdrop-filter: blur(1px);
  border: 1px solid rgba(91, 110, 247, 0.5);
  display: flex; align-items: center; justify-content: center;
  opacity: 0.15;
  transition: transform 0.3s ease, background 0.1s, opacity 0.3s ease;
  box-shadow: 0 8px 24px rgba(91, 110, 247, 0.25);
}
.media-card .mc-play svg { width: 42px; height: 42px; margin-left: 3px; fill: var(--blue); overflow: visible; }
.media-card .mc-play svg path {
  stroke: var(--blue);
  stroke-width: 5.2;
  stroke-linejoin: round;
  stroke-linecap: round;
  paint-order: stroke fill;
}
.media-card:hover .mc-play { transform: translate(-50%, -50%) scale(1.1); background: var(--blue); opacity: 1; }
.media-card:hover .mc-play svg { fill: #fff; }
.media-card:hover .mc-play svg path { stroke: #fff; }

/* 角落装饰 */
.media-card .corner {
  position: absolute; width: 14px; height: 14px; z-index: 4;
  border: 1px solid var(--blue); opacity: 0.65;
}
.media-card .corner.tl { top: 8px; left: 8px; border-right: none; border-bottom: none; }
.media-card .corner.tr { top: 8px; right: 8px; border-left: none; border-bottom: none; }
.media-card .corner.bl { bottom: 8px; left: 8px; border-right: none; border-top: none; }
.media-card .corner.br { bottom: 8px; right: 8px; border-left: none; border-top: none; }

/* 3 列 hover 放大 */
.media-3 .media-card { transition: flex 0.5s cubic-bezier(.2,.7,.2,1), transform 0.4s, border-color 0.3s, box-shadow 0.3s; }
.media-3:hover .media-card { flex: 1; }
.media-3 { display: flex; gap: 18px; }
.media-3 .media-card { flex: 1; min-width: 0; }
.media-3:hover .media-card:hover { flex: 2.4; }

/* ---------- 首页 / 尾页 ---------- */
.slide.cover .slide-inner { grid-template-rows: 1fr; place-items: center; text-align: center; }
.slide.cover .cover-wrap { display: flex; flex-direction: column; align-items: center; gap: 18px; }
.slide.cover .cover-kicker {
  font-family: var(--font-en); font-size: 13px; letter-spacing: 6px; color: var(--blue);
  padding: 6px 16px; border: 1px solid var(--line-strong); border-radius: 999px;
  background: rgba(255,255,255,0.6);
}
.slide.cover .cover-title {
  font-size: 76px; font-weight: 800; line-height: 1.1; letter-spacing: 2px;
  background: linear-gradient(135deg, #1a2240 0%, #4f6ef7 50%, #8b6cff 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  text-shadow: 0 0 60px rgba(91, 110, 247, 0.12);
}
.slide.cover .cover-title-next {
  margin-top: 6px;
  font-size: 34px; font-weight: 600; line-height: 1.3; letter-spacing: 4px;
  color: var(--ink-0);
  opacity: 0.85;
}
.slide.cover .cover-sub { font-size: 20px; color: var(--ink-1); letter-spacing: 4px; }
.slide.cover .cover-info { margin-top: 24px; display: flex; gap: 32px; color: var(--ink-2); font-family: var(--font-en); font-size: 13px; letter-spacing: 2px; }
.slide.cover .cover-info span { position: relative; }
.slide.cover .cover-info span + span::before { content: ""; position: absolute; left: -16px; top: 50%; width: 1px; height: 14px; background: var(--ink-2); transform: translateY(-50%); }

/* 封面：左图 + 右文 两栏布局 */
.slide.cover .cover-split {
  width: 100%;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  align-items: stretch;
  gap: 64px;
  text-align: left;
}
.slide.cover .cover-split .cover-wrap {
  align-items: flex-start;
  justify-content: center;
  text-align: left;
  height: 100%;
}
.slide.cover .cover-split .cover-title { font-size: 64px; }
.slide.cover .cover-split .cover-title-next { letter-spacing: 3px; }
.slide.cover .cover-split .cover-info { justify-content: flex-start; }

.cover-visual {
  position: relative;
  width: 100%;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--card-border);
  box-shadow: var(--shadow-3);
  backdrop-filter: blur(6px);
}
.cover-visual::after {
  content: "";
  position: absolute; inset: 0;
  border-radius: var(--radius-lg);
  pointer-events: none;
  box-shadow: inset 0 0 60px rgba(91, 110, 247, 0.10);
}
.cover-visual img { width: 100%; height: auto; display: block; }
.cover-visual .corner-deco {
  position: absolute; width: 22px; height: 22px;
  border: 1.5px solid var(--blue); opacity: 0.6;
}

.cover-visual-ph {
  min-height: 380px;
  background:
    linear-gradient(135deg, rgba(91, 110, 247, 0.10), rgba(139, 108, 255, 0.06)),
    repeating-linear-gradient(45deg, rgba(91, 110, 247, 0.05) 0 10px, transparent 10px 20px),
    #ffffff;
  display: flex; align-items: center; justify-content: center;
}
.cover-visual-ph .cv-ph {
  text-align: center;
  font-family: var(--font-en);
  color: var(--blue);
}
.cover-visual-ph .cv-ph strong { display: block; font-size: 26px; letter-spacing: 6px; font-weight: 700; }
.cover-visual-ph .cv-ph span { display: block; margin-top: 8px; font-size: 13px; letter-spacing: 3px; color: var(--ink-2); }

.slide.ending .ending-title {
  font-size: 88px; font-weight: 800; letter-spacing: 8px;
  background: var(--accent-grad);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.slide.ending .ending-sub { margin-top: 16px; font-size: 18px; color: var(--ink-1); letter-spacing: 6px; }

.slide-bg-img {
  position: absolute; inset: 0; z-index: -1;
  background-size: cover; background-position: center;
  opacity: 0.22;
  mask-image: radial-gradient(ellipse at center, #000 30%, transparent 80%);
}

/* ---------- 控制条 ---------- */
.controlbar {
  position: fixed; bottom: 18px; left: 50%; transform: translateX(-50%);
  z-index: 25;
  display: flex; align-items: center; gap: 14px;
  padding: 10px 18px;
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  backdrop-filter: blur(14px);
  box-shadow: 0 8px 28px rgba(91, 110, 247, 0.18);
}
.ctrl-btn {
  width: 38px; height: 38px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  color: var(--ink-1);
  border: 1px solid transparent;
  transition: all 0.25s ease;
}
.ctrl-btn:hover { color: var(--blue); border-color: var(--blue); background: rgba(91, 110, 247, 0.08); }
.ctrl-btn svg { width: 20px; height: 20px; }
.progress { width: 260px; height: 3px; background: rgba(91, 110, 247, 0.12); border-radius: 2px; overflow: hidden; }
.progress-bar { height: 100%; background: var(--accent-grad); width: 0%; transition: width 0.5s ease; box-shadow: 0 0 10px rgba(91,110,247,0.5); }

/* ---------- 目录 ---------- */
.toc {
  position: fixed; top: 0; right: -420px; width: 380px; height: 100%;
  background: rgba(255, 255, 255, 0.96); backdrop-filter: blur(20px);
  border-left: 1px solid var(--line-strong);
  z-index: 60; padding: 28px 24px;
  transition: right 0.4s cubic-bezier(.2,.7,.2,1);
  overflow-y: auto;
  box-shadow: -20px 0 50px rgba(91,110,247,0.12);
}
.toc.open { right: 0; }
.toc-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
.toc-head h3 { font-size: 14px; letter-spacing: 4px; color: var(--blue); font-family: var(--font-en); }
.toc-close { font-size: 28px; color: var(--ink-1); padding: 0 8px; line-height: 1; }
.toc-close:hover { color: var(--blue); }
.toc-list { list-style: none; counter-reset: toc; }
.toc-list li {
  counter-increment: toc;
  padding: 14px 16px; margin-bottom: 8px;
  border: 1px solid var(--card-border); border-radius: 10px;
  background: rgba(245, 247, 255, 0.7);
  cursor: pointer; transition: all 0.25s ease;
  display: flex; align-items: center; gap: 14px;
}
.toc-list li::before {
  content: counter(toc, decimal-leading-zero);
  font-family: var(--font-en); font-size: 13px; color: var(--blue);
  min-width: 28px;
}
.toc-list li:hover { border-color: var(--blue); background: rgba(91, 110, 247, 0.08); }
.toc-list li.current { border-color: var(--blue); background: rgba(91, 110, 247, 0.12); }
.toc-list li .ti { font-size: 14px; color: var(--ink-0); }
.toc-mask {
  position: fixed; inset: 0; background: rgba(20, 30, 70, 0.25); z-index: 55;
  opacity: 0; pointer-events: none; transition: opacity 0.3s;
  backdrop-filter: blur(2px);
}
.toc-mask.open { opacity: 1; pointer-events: auto; }

/* ---------- Lightbox ---------- */
.lightbox {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(245, 247, 255, 0.92); backdrop-filter: blur(12px);
  display: flex; align-items: center; justify-content: center;
  opacity: 0; pointer-events: none; transition: opacity 0.3s ease;
}
.lightbox.open { opacity: 1; pointer-events: auto; }
.lb-content {
  max-width: 92vw; max-height: 88vh;
  display: flex; align-items: center; justify-content: center;
  transform: scale(0.96); transition: transform 0.35s cubic-bezier(.2,.7,.2,1);
}
.lightbox.open .lb-content { transform: scale(1); }
.lb-content img, .lb-content video {
  max-width: 92vw; max-height: 88vh;
  border-radius: 10px; box-shadow: 0 30px 80px rgba(91, 110, 247, 0.25);
  border: 1px solid var(--line-strong);
}
.lb-caption {
  position: absolute; bottom: 24px; left: 50%; transform: translateX(-50%);
  color: var(--ink-0); font-size: 14px; letter-spacing: 2px;
  padding: 8px 18px; background: rgba(255, 255, 255, 0.85);
  border: 1px solid var(--line-strong); border-radius: 999px;
  box-shadow: 0 6px 20px rgba(91,110,247,0.12);
}
/* 描述卡片：仅在 item.content 存在时显示，浮动在右下角 */
.lb-desc {
  position: absolute; right: 28px; bottom: 24px;
  max-width: 340px; max-height: 50vh; overflow-y: auto;
  padding: 14px 18px;
  color: var(--ink-0); font-size: 14px; line-height: 1.7;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--line-strong); border-radius: 14px;
  box-shadow: 0 12px 30px rgba(91, 110, 247, 0.18);
  backdrop-filter: blur(6px);
  white-space: pre-wrap; word-break: break-word;
  scrollbar-width: thin;
}
.lb-desc[hidden] { display: none; }
.lb-close, .tb-close {
  position: absolute; top: 24px; right: 28px; z-index: 5;
  width: 44px; height: 44px; border-radius: 50%;
  background: rgba(255, 255, 255, 0.9); border: 1px solid var(--line-strong);
  color: var(--ink-0); font-size: 24px; line-height: 40px;
  transition: all 0.25s ease;
  box-shadow: 0 6px 18px rgba(91,110,247,0.15);
}
.lb-close:hover, .tb-close:hover { background: var(--blue); color: #fff; border-color: var(--blue); }

/* ---------- 全屏文本面板 ---------- */
.textbox {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(245, 247, 255, 0.94); backdrop-filter: blur(14px);
  display: flex; align-items: center; justify-content: center;
  opacity: 0; pointer-events: none; transition: opacity 0.3s ease;
}
.textbox.open { opacity: 1; pointer-events: auto; }
.tb-inner {
  max-width: 1100px; width: 86vw; max-height: 80vh;
  overflow-y: auto;
  padding: 60px 70px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.95), rgba(248, 250, 255, 0.95));
  border: 1px solid var(--line-strong); border-radius: var(--radius-lg);
  box-shadow: 0 30px 80px rgba(91, 110, 247, 0.20);
  transform: scale(0.96); transition: transform 0.35s cubic-bezier(.2,.7,.2,1);
}
.textbox.open .tb-inner { transform: scale(1); }
.tb-inner h2 {
  font-size: 32px; margin-bottom: 24px; letter-spacing: 1px;
  background: linear-gradient(135deg, #1a2240, #4f6ef7 60%, #8b6cff);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  border-bottom: 1px solid var(--line); padding-bottom: 16px;
}
.tb-body { color: var(--ink-1); font-size: 17px; line-height: 1.9; letter-spacing: 0.5px; }
.tb-body p { margin-bottom: 14px; }
.tb-body ul { margin: 10px 0 14px 22px; }
.tb-body li { margin-bottom: 6px; }
.tb-body strong { color: var(--ink-0); }
.tb-body h3 { color: var(--blue); margin: 18px 0 10px; font-size: 18px; letter-spacing: 1px; }
.tb-body code { background: rgba(91,110,247,0.10); color: var(--blue); padding: 2px 6px; border-radius: 4px; font-size: 14px; }

/* 滚动条 */
.tb-inner::-webkit-scrollbar, .toc::-webkit-scrollbar { width: 6px; }
.tb-inner::-webkit-scrollbar-thumb, .toc::-webkit-scrollbar-thumb { background: rgba(91,110,247,0.3); border-radius: 3px; }
.tb-inner::-webkit-scrollbar-track, .toc::-webkit-scrollbar-track { background: rgba(91,110,247,0.05); }

/* ---------- 占位卡（浅色） ---------- */
.media-card.placeholder {
  background:
    linear-gradient(135deg, rgba(91, 110, 247, 0.10), rgba(139, 108, 255, 0.06)),
    repeating-linear-gradient(45deg, rgba(91, 110, 247, 0.04) 0 10px, transparent 10px 20px),
    rgba(255, 255, 255, 0.7);
  display: flex; align-items: center; justify-content: center;
}
.media-card.placeholder::before { background: none; }
.media-card.placeholder .mc-title,
.media-card.placeholder .mc-sub { color: var(--ink-0); text-shadow: none; }
.media-card.placeholder .mc-sub { color: var(--ink-1); }
.media-card.placeholder .ph-text {
  font-family: var(--font-en); font-size: 13px; color: var(--ink-2); letter-spacing: 3px;
  text-align: center; padding: 12px;
}
.media-card.placeholder .ph-text strong { display: block; color: var(--blue); font-size: 22px; margin-bottom: 8px; letter-spacing: 4px; font-weight: 600; }

/* ---------- Lightbox 占位 & 空状态 ---------- */
.lb-placeholder {
  width: min(70vw, 1200px);
  aspect-ratio: 16 / 9;
  display: flex; align-items: center; justify-content: center;
  background:
    linear-gradient(135deg, rgba(91, 110, 247, 0.12), rgba(139, 108, 255, 0.08)),
    repeating-linear-gradient(45deg, rgba(91, 110, 247, 0.05) 0 10px, transparent 10px 20px),
    #ffffff;
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  color: var(--blue);
  font-family: var(--font-en);
  letter-spacing: 4px;
  font-size: 22px;
  box-shadow: 0 20px 60px rgba(91, 110, 247, 0.18);
}
.stage-empty {
  color: var(--blue);
  font-size: 20px;
  letter-spacing: 2px;
  font-family: var(--font-en);
}

/* ---------- 自适应 ---------- */
@media (max-width: 1280px) {
  .slide-title { font-size: 30px; }
  .slide.cover .cover-title { font-size: 56px; }
  .slide { padding: 60px 40px 80px; }
}