/* ══════════════════════════════════
   方案C — 单页滚动故事
   核心：每个功能是一个全屏"帧"
   滚动触发截图从底部推入 + 文字淡入
══════════════════════════════════ */

/* ─── 全局重置（方案C专用覆盖）─── */
html { scroll-behavior: auto; } /* 由JS接管 */

/* ══════════════════════════════════
   HERO
══════════════════════════════════ */
.c-hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  text-align: left;
  padding: 0 calc((100vw - 1080px) / 2);
  padding-left: max(40px, calc((100vw - 1080px) / 2));
  position: relative;
  overflow: hidden;
  background: var(--bg);
}

.c-hero-noise {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 90% 80% at 50% 50%, #1e0d03 0%, transparent 60%);
  pointer-events: none;
}

/* 背景粒子线条 */
.c-hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(193,95,60,.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(193,95,60,.04) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black 0%, transparent 70%);
  pointer-events: none;
}

.c-hero-eyebrow {
  font-size: 11px;
  letter-spacing: .55em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 48px;
  position: relative;
  z-index: 1;
  opacity: 0;
  animation: fadeUp .8s var(--ease-out) .3s forwards;
}

.c-hero-title {
  font-size: clamp(56px, 9vw, 120px);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -.04em;
  margin-bottom: 32px;
  max-width: 1000px;
  position: relative;
  z-index: 1;
  opacity: 0;
  animation: fadeUp .9s var(--ease-out) .5s forwards;
}

.c-hero-title em {
  color: var(--gold);
  font-style: normal;
}

.c-hero-sub {
  font-size: clamp(15px, 1.8vw, 19px);
  color: var(--muted);
  margin-bottom: 60px;
  letter-spacing: .08em;
  position: relative;
  z-index: 1;
  opacity: 0;
  animation: fadeUp .9s var(--ease-out) .7s forwards;
}

.c-hero-actions {
  display: flex;
  gap: 14px;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
  opacity: 0;
  animation: fadeUp .9s var(--ease-out) .9s forwards;
}

/* 向下滚动提示 */
.c-scroll-hint {
  position: absolute;
  bottom: 44px;
  left: max(40px, calc((100vw - 1080px) / 2));
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  opacity: 0;
  animation: fadeUp .9s var(--ease-out) 1.4s forwards;
  z-index: 1;
}

.c-scroll-hint-text {
  font-size: 10px;
  letter-spacing: .4em;
  color: var(--muted);
  text-transform: uppercase;
}

.c-scroll-hint-line {
  width: 1px;
  height: 48px;
  background: linear-gradient(to bottom, var(--accent), transparent);
  animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
  0%, 100% { opacity: .3; transform: scaleY(1); }
  50%       { opacity: 1;  transform: scaleY(1.15); }
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}


/* ══════════════════════════════════
   STORY FRAMES
   每帧 = 1个全屏 section，
   内容在滚动到视口时触发动画
══════════════════════════════════ */

.story-frame {
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto 1fr;
  padding: 120px 0 80px;
  position: relative;
  overflow: hidden;
}

/* 奇数帧：深背景 */
.story-frame:nth-child(odd) {
  background: var(--bg);
}

/* 偶数帧：略有区分 */
.story-frame:nth-child(even) {
  background: #0d0d0d;
}

/* 帧内布局 */
.sf-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
}

/* ── 文字区（帧顶部，居中） ── */
.sf-text {
  text-align: center;
  padding: 0 40px;
  margin-bottom: 72px;
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
}

.sf-num {
  font-size: 10px;
  letter-spacing: .55em;
  color: var(--accent);
  text-transform: uppercase;
  font-family: var(--font-mono);
  display: block;
  margin-bottom: 24px;

  /* 入场动画 */
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .7s var(--ease-out), transform .7s var(--ease-out);
}

.sf-heading {
  font-size: clamp(40px, 5.5vw, 72px);
  font-weight: 900;
  line-height: 1.22;
  letter-spacing: -.035em;
  margin-bottom: 20px;

  opacity: 0;
  transform: translateY(20px);
  transition: opacity .75s var(--ease-out) .1s, transform .75s var(--ease-out) .1s;
}

.sf-heading em { color: var(--gold); font-style: normal; }

.sf-desc {
  font-size: clamp(14px, 1.5vw, 17px);
  color: var(--text-dim);
  line-height: 1.9;

  opacity: 0;
  transform: translateY(16px);
  transition: opacity .7s var(--ease-out) .22s, transform .7s var(--ease-out) .22s;
}

/* ── 截图区（从底部推入）── */
.sf-screen {
  width: 100%;
  max-width: 1300px;
  padding: 0 24px;
  margin: 0 auto;

  opacity: 0;
  transform: translateY(60px);
  transition: opacity .85s var(--ease-out) .15s, transform .85s var(--ease-out) .15s;
}

.sf-screen img {
  width: 100%;
  display: block;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow:
    0 2px 0 rgba(255,255,255,.04),
    0 48px 120px rgba(0,0,0,.8);
}

/* 截图：双图并排 */
.sf-screen-duo {
  width: 100%;
  max-width: 1300px;
  padding: 0 24px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  align-items: start;

  opacity: 0;
  transform: translateY(60px);
  transition: opacity .85s var(--ease-out) .15s, transform .85s var(--ease-out) .15s;
}

.sf-screen-duo-item {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.sf-screen-duo-item img {
  width: 100%;
  display: block;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  box-shadow: 0 24px 80px rgba(0,0,0,.65);
}

.sf-caption {
  font-size: 11px;
  letter-spacing: .25em;
  color: var(--muted);
  text-align: center;
  text-transform: uppercase;
}

/* ── 帧激活时：所有元素入场 ── */
.story-frame.in-view .sf-num,
.story-frame.in-view .sf-heading,
.story-frame.in-view .sf-desc,
.story-frame.in-view .sf-screen,
.story-frame.in-view .sf-screen-duo {
  opacity: 1;
  transform: translateY(0);
}

/* 底部光晕装饰 */
.story-frame::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0; right: 0;
  height: 1px;
  background: linear-gradient(to right, transparent, var(--border), transparent);
}


/* ══════════════════════════════════
   EXPORT FRAME（特殊：不用 story-frame）
══════════════════════════════════ */
.export-frame {
  padding: 140px 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% 20%, #180e04 0%, transparent 55%),
    #0a0a0a;
  position: relative;
}

.export-frame-header {
  text-align: center;
  padding: 0 40px;
  margin-bottom: 64px;
}

.export-frame-num {
  font-size: 10px;
  letter-spacing: .55em;
  color: var(--accent);
  text-transform: uppercase;
  font-family: var(--font-mono);
  display: block;
  margin-bottom: 24px;
}

.export-frame-heading {
  font-size: clamp(40px, 5.5vw, 72px);
  font-weight: 900;
  line-height: 1.22;
  letter-spacing: -.035em;
  margin-bottom: 16px;
}

.export-frame-heading em { color: var(--accent); font-style: normal; }

.export-frame-sub {
  font-size: 17px;
  color: var(--muted);
  letter-spacing: .06em;
  margin-bottom: 52px;
}

/* Tab 导航 */
.c-export-tabs {
  display: flex;
  justify-content: center;
  gap: 4px;
  margin-bottom: 72px;
  background: rgba(255,255,255,.04);
  border: 1px solid var(--border);
  border-radius: 60px;
  padding: 5px;
  width: fit-content;
  margin-left: auto;
  margin-right: auto;
}

.c-export-tab {
  padding: 10px 32px;
  border-radius: 60px;
  font-size: 14px;
  color: var(--muted);
  letter-spacing: .04em;
  transition: background .25s, color .25s;
  font-family: var(--font-serif);
  cursor: pointer;
}

.c-export-tab.active {
  background: var(--accent);
  color: #fff;
}

.c-export-tab:not(.active):hover { color: var(--text); }

/* 面板 */
.c-export-panels { position: relative; }
.c-export-panel  { display: none; }
.c-export-panel.active { display: block; }

/* ── 小红书：大图聚焦 + 缩略图 ── */
.c-xhs-intro {
  text-align: center;
  padding: 0 40px;
  margin-bottom: 56px;
}

.c-xhs-intro p {
  font-size: 17px;
  color: var(--muted);
  line-height: 1.9;
  max-width: 500px;
  margin: 0 auto;
}

.xhs-gallery {
  display: grid;
  grid-template-columns: 1fr 72px;
  gap: 14px;
  max-width: 680px;
  margin: 0 auto;
  padding: 0 24px;
  align-items: start;
}

/* 大图区：固定高度，不溢出视窗 */
.xhs-main {
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: 0 20px 60px rgba(0,0,0,.7);
  background: #0e0e0e;
  height: 500px;
}

.xhs-main img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
  display: block;
  transition: opacity .3s ease;
}

.xhs-main img.switching {
  opacity: 0;
}

/* 缩略图列 */
.xhs-thumbs {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.xhs-thumb {
  border-radius: 6px;
  overflow: hidden;
  border: 2px solid transparent;
  cursor: pointer;
  opacity: .4;
  transition: opacity .25s ease, border-color .25s ease, transform .25s ease;
}

.xhs-thumb:hover {
  opacity: .75;
  transform: translateX(-3px);
}

.xhs-thumb.active {
  opacity: 1;
  border-color: var(--accent);
}

.xhs-thumb img {
  width: 100%;
  display: block;
}

/* 双图导出 */
.c-export-duo {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  align-items: start;
}

.c-export-duo-item {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.c-export-duo-item img {
  width: 100%;
  display: block;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  box-shadow: 0 24px 80px rgba(0,0,0,.6);
  transition: transform .5s var(--ease-out);
}

.c-export-duo-item img:hover { transform: translateY(-4px); }

.c-export-duo-caption {
  font-size: 11px;
  letter-spacing: .25em;
  color: var(--muted);
  text-align: center;
  text-transform: uppercase;
}

.c-export-duo-desc {
  text-align: center;
  padding: 0 40px;
  margin-bottom: 52px;
  font-size: 16px;
  color: var(--muted);
  line-height: 1.85;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}


/* ══════════════════════════════════
   TRAITS FRAME
══════════════════════════════════ */
.traits-frame {
  padding: 140px 0;
  background: var(--bg);
}

.traits-frame-header {
  text-align: center;
  padding: 0 40px;
  margin-bottom: 80px;
}

.traits-frame-num {
  font-size: 10px;
  letter-spacing: .55em;
  color: var(--accent);
  text-transform: uppercase;
  font-family: var(--font-mono);
  display: block;
  margin-bottom: 24px;
}

.traits-frame-heading {
  font-size: clamp(36px, 5vw, 60px);
  font-weight: 900;
  letter-spacing: -.03em;
  margin-bottom: 14px;
}

.traits-frame-sub {
  font-size: 16px;
  color: var(--muted);
  letter-spacing: .06em;
}

.c-traits-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--border2);
  border-left: 1px solid var(--border2);
}

.c-trait {
  border-right: 1px solid var(--border2);
  border-bottom: 1px solid var(--border2);
  padding: 52px 44px;
  transition: background .35s ease;

  opacity: 0;
  transform: translateY(20px);
  transition:
    background .35s ease,
    opacity .65s var(--ease-out),
    transform .65s var(--ease-out);
}

.c-trait.in-view {
  opacity: 1;
  transform: translateY(0);
}

.c-trait:nth-child(1) { transition-delay: .05s; }
.c-trait:nth-child(2) { transition-delay: .12s; }
.c-trait:nth-child(3) { transition-delay: .19s; }
.c-trait:nth-child(4) { transition-delay: .26s; }
.c-trait:nth-child(5) { transition-delay: .33s; }
.c-trait:nth-child(6) { transition-delay: .40s; }

.c-trait:hover { background: #0e0a06; }

.c-trait-num {
  display: block;
  font-size: 11px;
  letter-spacing: .4em;
  color: var(--accent);
  margin-bottom: 24px;
  font-family: var(--font-mono);
}

.c-trait-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 12px;
}

.c-trait-desc {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.85;
}


/* ══════════════════════════════════
   DOWNLOAD FRAME
══════════════════════════════════ */
.download-frame {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 120px 40px;
  position: relative;
  overflow: hidden;
  background: var(--bg);
}

.download-frame::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 70% at 50% 50%, #1e1108 0%, transparent 65%);
  pointer-events: none;
}

.c-dl-num {
  font-size: 10px;
  letter-spacing: .55em;
  color: var(--accent);
  text-transform: uppercase;
  font-family: var(--font-mono);
  margin-bottom: 32px;
  position: relative;
  z-index: 1;

  opacity: 0;
  transform: translateY(16px);
  transition: opacity .7s var(--ease-out), transform .7s var(--ease-out);
}

.c-dl-title {
  font-size: clamp(56px, 9vw, 120px);
  font-weight: 900;
  letter-spacing: -.04em;
  line-height: 1.18;
  margin-bottom: 20px;
  position: relative;
  z-index: 1;

  opacity: 0;
  transform: translateY(24px);
  transition: opacity .8s var(--ease-out) .1s, transform .8s var(--ease-out) .1s;
}

.c-dl-title em { color: var(--accent); font-style: normal; }

.c-dl-version {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: .22em;
  font-family: var(--font-mono);
  margin-bottom: 52px;
  position: relative;
  z-index: 1;

  opacity: 0;
  transform: translateY(16px);
  transition: opacity .7s var(--ease-out) .2s, transform .7s var(--ease-out) .2s;
}

.c-dl-buttons {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 32px;
  position: relative;
  z-index: 1;

  opacity: 0;
  transform: translateY(16px);
  transition: opacity .7s var(--ease-out) .3s, transform .7s var(--ease-out) .3s;
}

.c-dl-sys {
  font-size: 12px;
  color: #3a3a38;
  letter-spacing: .08em;
  margin-bottom: 16px;
  position: relative;
  z-index: 1;

  opacity: 0;
  transition: opacity .7s var(--ease-out) .4s;
}

.c-dl-online {
  font-size: 14px;
  color: var(--muted);
  position: relative;
  z-index: 1;

  opacity: 0;
  transition: opacity .7s var(--ease-out) .5s;
}

.c-dl-online a {
  color: var(--gold);
  border-bottom: 1px solid rgba(184,160,128,.3);
  transition: border-color .2s;
}

.c-dl-online a:hover { border-color: var(--gold); }

/* ── Tscore 合作横条 ── */
.tscore-banner {
  display: flex;
  align-items: center;
  gap: 20px;
  margin: 36px auto 0;
  padding: 18px 32px;
  border: 1px solid rgba(184,160,128,.15);
  border-radius: 60px;
  background: rgba(184,160,128,.04);
  width: fit-content;
  position: relative;
  z-index: 1;
  transition: border-color .3s ease, background .3s ease;
}

.tscore-banner:hover {
  border-color: rgba(184,160,128,.35);
  background: rgba(184,160,128,.08);
}

.tscore-banner-text {
  font-size: 13px;
  color: var(--muted);
  letter-spacing: .04em;
  white-space: nowrap;
}

.tscore-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  transition: gap .25s ease;
}

.tscore-btn:hover {
  gap: 14px;
}

/* Tscore 字标：T 用金色粗体，score 用细体 */
.tscore-wordmark {
  font-family: 'Noto Serif SC', 'Songti SC', serif;
  font-size: 17px;
  font-weight: 900;
  color: var(--gold);
  letter-spacing: -.01em;
  line-height: 1;
}

.tscore-wordmark em {
  font-style: normal;
  font-weight: 400;
  color: rgba(184,160,128,.7);
  letter-spacing: .02em;
}

.tscore-arrow {
  font-size: 14px;
  color: rgba(184,160,128,.5);
  font-family: var(--font-mono);
  transition: color .25s ease, transform .25s ease;
}

.tscore-btn:hover .tscore-arrow {
  color: var(--gold);
  transform: translateX(3px);
}

/* 下载帧激活 */
.download-frame.in-view .c-dl-num,
.download-frame.in-view .c-dl-title,
.download-frame.in-view .c-dl-version,
.download-frame.in-view .c-dl-buttons,
.download-frame.in-view .c-dl-sys,
.download-frame.in-view .c-dl-online {
  opacity: 1;
  transform: translateY(0);
}


/* ══════════════════════════════════
   BUTTONS（同方案B，复用）
══════════════════════════════════ */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 15px 44px;
  background: var(--accent);
  color: #fff;
  border-radius: 60px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .06em;
  transition: background .25s, transform .25s, box-shadow .25s;
}

.btn-primary:hover {
  background: #d06840;
  transform: translateY(-2px);
  box-shadow: 0 14px 52px rgba(193,95,60,.42);
}

.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 36px;
  border: 1px solid rgba(255,255,255,.1);
  border-radius: 60px;
  font-size: 14px;
  color: var(--muted);
  transition: border-color .25s, color .25s;
}

.btn-ghost:hover {
  border-color: rgba(193,95,60,.5);
  color: var(--text);
}

.btn-download-main {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 56px;
  background: var(--accent);
  color: #fff;
  border-radius: 60px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: .06em;
  transition: background .25s, transform .25s, box-shadow .25s;
}

.btn-download-main:hover {
  background: #d06840;
  transform: translateY(-2px);
  box-shadow: 0 16px 60px rgba(193,95,60,.45);
}

.btn-download-ghost {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 15px 44px;
  border: 1px solid rgba(255,255,255,.1);
  border-radius: 60px;
  font-size: 15px;
  color: var(--muted);
  transition: border-color .25s, color .25s;
}

.btn-download-ghost:hover {
  border-color: rgba(193,95,60,.5);
  color: var(--text);
}


/* ══════════════════════════════════
   RESPONSIVE
══════════════════════════════════ */
@media (max-width: 960px) {
  .sf-screen-duo,
  .c-export-duo { grid-template-columns: 1fr; }

  .c-traits-grid { grid-template-columns: 1fr 1fr; }

  .c-hero-title { font-size: clamp(44px, 10vw, 80px); }

  .nav-links li:not(:last-child):not(:nth-last-child(2)) { display: none; }
}

@media (max-width: 600px) {
  .c-traits-grid  { grid-template-columns: 1fr; }
  .c-export-tabs  { flex-wrap: wrap; border-radius: var(--radius-md); }
  .c-hero         { padding: 0 24px; }
  .story-frame    { padding: 80px 0 60px; }
}