/* ==========================================================================
   岐衡 QiHeng TCM - Official Design System (Vanilla CSS)
   ========================================================================== */

:root {
  /* Brand Color Palette - TCM Cinnabar, Bamboo Jade & Amber Gold */
  --brand-cinnabar: #C23B22;
  --brand-cinnabar-glow: rgba(194, 59, 34, 0.25);
  --brand-cinnabar-dark: #9E2B16;
  --brand-jade: #2E6F56;
  --brand-jade-glow: rgba(46, 111, 86, 0.22);
  --brand-gold: #C89B3C;
  --brand-gold-subtle: rgba(200, 155, 60, 0.15);

  /* Surfaces & Backgrounds */
  --bg-main: #0B0D11;
  --bg-gradient: radial-gradient(circle at 50% 0%, #1E1A1A 0%, #0B0D11 75%);
  --surface-card: #15181E;
  --surface-card-hover: #1C2028;
  --surface-elevated: #222731;
  --surface-glass: rgba(21, 24, 30, 0.75);
  
  /* Borders & Dividers */
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-active: rgba(194, 59, 34, 0.45);
  --border-gold: rgba(200, 155, 60, 0.35);

  /* Typography */
  --font-serif: "Noto Serif SC", serif;
  --font-sans: "Plus Jakarta Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  
  --text-primary: #F3F4F6;
  --text-secondary: #9CA3AF;
  --text-muted: #6B7280;
  --text-gold: #E5C378;

  /* Shadows */
  --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.45);
  --shadow-glow: 0 0 35px var(--brand-cinnabar-glow);
  --shadow-gold-glow: 0 0 30px var(--brand-gold-subtle);

  /* Layout */
  --container-max: 1200px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 32px;
}

/* --------------------------------------------------------------------------
   Reset & Global Baseline
   -------------------------------------------------------------------------- */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
}

body {
  background: var(--bg-gradient);
  min-height: 100vh;
  line-height: 1.6;
  overflow-x: hidden;
}

/* --------------------------------------------------------------------------
   Site Header & Floating Navigation
   -------------------------------------------------------------------------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--surface-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
  transition: all 0.3s ease;
}

.header-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
}

.brand-icon {
  width: 44px;
  height: 44px;
  border-radius: 11px;
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.5px;
}

.brand-sub {
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 1px;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--brand-cinnabar);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.btn-lang {
  background: var(--surface-elevated);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-lang:hover {
  border-color: var(--brand-cinnabar);
  color: var(--brand-cinnabar);
}

.btn-appstore-header {
  background: linear-gradient(135deg, var(--brand-cinnabar), var(--brand-cinnabar-dark));
  color: #FFFFFF;
  padding: 8px 18px;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  box-shadow: 0 4px 14px rgba(194, 59, 34, 0.35);
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.btn-appstore-header:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(194, 59, 34, 0.45);
}

/* --------------------------------------------------------------------------
   Hero Section
   -------------------------------------------------------------------------- */
.hero-section {
  padding: 160px 24px 80px;
  max-width: var(--container-max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 60px;
}

.hero-content {
  display: flex;
  flex-direction: column;
}

.hero-badge-container {
  margin-bottom: 20px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(194, 59, 34, 0.12);
  border: 1px solid rgba(194, 59, 34, 0.3);
  border-radius: 100px;
  color: var(--text-gold);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.5px;
}

.hero-title {
  font-family: var(--font-serif);
  font-size: 3.4rem;
  font-weight: 700;
  line-height: 1.22;
  margin-bottom: 20px;
  color: #FFFFFF;
}

.hero-title span.highlight {
  background: linear-gradient(135deg, #FF6B50, var(--brand-gold));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 36px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.btn-appstore-large {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  background: #FFFFFF;
  color: #000000;
  padding: 12px 26px;
  border-radius: var(--radius-md);
  text-decoration: none;
  font-weight: 600;
  box-shadow: 0 10px 30px rgba(255, 255, 255, 0.15);
  transition: all 0.25s ease;
}

.btn-appstore-large:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 36px rgba(255, 255, 255, 0.25);
}

.btn-appstore-large svg {
  width: 28px;
  height: 28px;
}

.btn-appstore-text {
  display: flex;
  flex-direction: column;
  text-align: left;
}

.btn-appstore-sub {
  font-size: 0.72rem;
  text-transform: uppercase;
  color: #555;
  line-height: 1;
}

.btn-appstore-main {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.2;
}

.hero-privacy-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--brand-jade);
  font-size: 0.9rem;
  font-weight: 600;
}

.hero-highlights-row {
  display: flex;
  gap: 28px;
  padding-top: 24px;
  border-top: 1px solid var(--border-subtle);
}

.highlight-item {
  display: flex;
  flex-direction: column;
}

.highlight-item .number {
  font-family: var(--font-serif);
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text-gold);
}

.highlight-item .label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
}

.hero-phone-mockup {
  width: 100%;
  max-width: 360px;
  border-radius: 40px;
  box-shadow: var(--shadow-glow), var(--shadow-md);
  border: 8px solid #22262E;
  overflow: hidden;
  transition: transform 0.4s ease;
}

.hero-phone-mockup:hover {
  transform: scale(1.02);
}

.hero-phone-mockup img {
  width: 100%;
  display: block;
}

/* --------------------------------------------------------------------------
   Interactive Meridian Clock Showcase (子午流注互动体验)
   -------------------------------------------------------------------------- */
.section-meridian {
  padding: 100px 24px;
  max-width: var(--container-max);
  margin: 0 auto;
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-tag {
  color: var(--brand-cinnabar);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  display: block;
  margin-bottom: 12px;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 2.6rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: #FFFFFF;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto;
}

.meridian-interactive-card {
  background: var(--surface-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 44px;
  box-shadow: var(--shadow-md);
  display: grid;
  grid-template-columns: 1fr 1.15fr;
  gap: 48px;
  align-items: center;
}

.meridian-wheel-container {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.meridian-hours-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  width: 100%;
  max-width: 440px;
}

.meridian-hour-btn {
  background: var(--surface-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 12px 8px;
  color: var(--text-primary);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.meridian-hour-btn .zodiac {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 700;
}

.meridian-hour-btn .time-range {
  font-size: 0.72rem;
  color: var(--text-muted);
}

.meridian-hour-btn .organ-name {
  font-size: 0.8rem;
  color: var(--text-gold);
}

.meridian-hour-btn:hover {
  border-color: var(--brand-cinnabar);
  background: var(--surface-card-hover);
}

.meridian-hour-btn.active {
  background: linear-gradient(135deg, rgba(194, 59, 34, 0.25), rgba(200, 155, 60, 0.15));
  border-color: var(--brand-cinnabar);
  box-shadow: 0 0 18px var(--brand-cinnabar-glow);
}

.meridian-detail-panel {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.meridian-badge-active {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: rgba(200, 155, 60, 0.15);
  border: 1px solid var(--border-gold);
  border-radius: 100px;
  color: var(--text-gold);
  font-size: 0.85rem;
  font-weight: 600;
  width: fit-content;
}

.meridian-detail-title {
  font-family: var(--font-serif);
  font-size: 2.2rem;
  font-weight: 700;
  color: #FFFFFF;
}

.meridian-detail-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.meridian-meta-boxes {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 8px;
}

.meta-box {
  background: var(--surface-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 16px;
}

.meta-box .meta-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 4px;
  text-transform: uppercase;
}

.meta-box .meta-val {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* --------------------------------------------------------------------------
   Nine Constitutions Interactive Explorer (九种体质智能测评)
   -------------------------------------------------------------------------- */
.section-constitutions {
  padding: 100px 24px;
  max-width: var(--container-max);
  margin: 0 auto;
}

.constitution-tabs-container {
  display: flex;
  gap: 10px;
  overflow-x: auto;
  padding-bottom: 16px;
  margin-bottom: 36px;
  scrollbar-width: none;
}

.constitution-tabs-container::-webkit-scrollbar {
  display: none;
}

.con-tab-btn {
  background: var(--surface-card);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  padding: 10px 20px;
  border-radius: 100px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s ease;
}

.con-tab-btn:hover {
  color: #FFFFFF;
  border-color: rgba(255, 255, 255, 0.2);
}

.con-tab-btn.active {
  background: var(--brand-cinnabar);
  border-color: var(--brand-cinnabar);
  color: #FFFFFF;
  box-shadow: 0 4px 16px rgba(194, 59, 34, 0.4);
}

.constitution-display-card {
  background: var(--surface-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 44px;
  box-shadow: var(--shadow-md);
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
  align-items: center;
}

.con-info-content h3 {
  font-family: var(--font-serif);
  font-size: 2.2rem;
  color: #FFFFFF;
  margin-bottom: 12px;
}

.con-features-list {
  margin: 20px 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.con-feature-item {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 1rem;
  color: var(--text-secondary);
}

.con-feature-item::before {
  content: "•";
  color: var(--brand-cinnabar);
  font-size: 1.4rem;
  line-height: 1;
}

.con-advice-box {
  background: var(--surface-elevated);
  border-left: 4px solid var(--brand-jade);
  padding: 16px 20px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin-top: 16px;
}

.con-advice-box strong {
  color: var(--brand-jade);
  display: block;
  margin-bottom: 4px;
  font-size: 0.95rem;
}

.con-visual-preview {
  display: flex;
  justify-content: center;
}

.con-visual-preview img {
  width: 100%;
  max-width: 320px;
  border-radius: 28px;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-subtle);
}

/* --------------------------------------------------------------------------
   Acupoints & Metronome Haptic Showcase (经穴与触觉节拍器)
   -------------------------------------------------------------------------- */
.section-features-grid {
  padding: 100px 24px;
  max-width: var(--container-max);
  margin: 0 auto;
}

.grid-4-col {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

@media (max-width: 1024px) {
  .grid-4-col {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .grid-4-col {
    grid-template-columns: 1fr;
  }
}

.feature-box {
  background: var(--surface-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
}

.feature-box:hover {
  transform: translateY(-4px);
  border-color: var(--border-active);
  box-shadow: var(--shadow-md);
}

.feature-box-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 24px;
  background: var(--surface-elevated);
  border: 1px solid var(--border-subtle);
}

.feature-box h3 {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  color: #FFFFFF;
  margin-bottom: 12px;
}

.feature-box p {
  color: var(--text-secondary);
  font-size: 0.98rem;
  line-height: 1.7;
}

/* --------------------------------------------------------------------------
   App Store Screenshots Gallery
   -------------------------------------------------------------------------- */
.section-gallery {
  padding: 100px 24px;
  max-width: var(--container-max);
  margin: 0 auto;
}

.gallery-scroller {
  display: flex;
  gap: 24px;
  overflow-x: auto;
  padding: 20px 8px 40px;
  scroll-snap-type: x mandatory;
}

.gallery-item {
  flex: 0 0 280px;
  scroll-snap-align: center;
  border-radius: 24px;
  overflow: hidden;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-subtle);
  transition: transform 0.3s ease;
}

.gallery-item:hover {
  transform: translateY(-6px);
  border-color: var(--border-active);
}

.gallery-item img {
  width: 100%;
  display: block;
}

/* --------------------------------------------------------------------------
   Privacy & Security Manifesto (100% 离线沙盒承诺)
   -------------------------------------------------------------------------- */
.section-privacy-banner {
  padding: 80px 24px;
  max-width: var(--container-max);
  margin: 0 auto;
}

.privacy-banner-card {
  background: linear-gradient(135deg, #161A22 0%, #1A1716 100%);
  border: 1px solid rgba(46, 111, 86, 0.4);
  border-radius: var(--radius-xl);
  padding: 56px 48px;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
  align-items: center;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
}

.privacy-banner-card h2 {
  font-family: var(--font-serif);
  font-size: 2.4rem;
  color: #FFFFFF;
  margin-bottom: 16px;
}

.privacy-banner-card p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.8;
  margin-bottom: 24px;
}

.privacy-points-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.priv-point {
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  padding: 16px;
}

.priv-point h4 {
  color: var(--brand-jade);
  font-size: 1rem;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.priv-point p {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin: 0;
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.site-footer {
  background: #08090C;
  border-top: 1px solid var(--border-subtle);
  padding: 60px 24px 40px;
}

.footer-container {
  max-width: var(--container-max);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
}

.footer-brand .brand-title {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  color: #FFFFFF;
  font-weight: 700;
}

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-top: 4px;
}

.footer-links {
  display: flex;
  gap: 28px;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: var(--brand-cinnabar);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  color: var(--text-muted);
  font-size: 0.85rem;
  flex-wrap: wrap;
  gap: 16px;
}

/* --------------------------------------------------------------------------
   Responsive Breakpoints
   -------------------------------------------------------------------------- */
@media (max-width: 968px) {
  .hero-section {
    grid-template-columns: 1fr;
    text-align: center;
    padding-top: 130px;
  }
  .hero-content {
    align-items: center;
  }
  .hero-title {
    font-size: 2.6rem;
  }
  .hero-highlights-row {
    justify-content: center;
  }
  .meridian-interactive-card,
  .constitution-display-card,
  .privacy-banner-card {
    grid-template-columns: 1fr;
  }
  .grid-4-col {
    grid-template-columns: 1fr;
  }
  .nav-links {
    display: none;
  }
}