/* ===== Design Tokens ===== */
:root {
  --color-bg: #000000;
  --color-surface: rgba(15, 15, 20, 0.85);
  --color-surface-hover: rgba(25, 25, 35, 0.9);
  --color-border: rgba(255, 255, 255, 0.06);
  --color-border-hover: rgba(245, 158, 11, 0.25);
  --color-text: #e2e8f0;
  --color-text-muted: #94a3b8;
  --color-text-dim: #64748b;
  --color-amber: #f59e0b;
  --color-amber-light: #fbbf24;
  --color-amber-glow: rgba(245, 158, 11, 0.15);
  --color-amber-glow-strong: rgba(245, 158, 11, 0.4);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --radius-pill: 9999px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  overflow-x: hidden;
}

::selection {
  background: rgba(245, 158, 11, 0.3);
  color: #fef3c7;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }

/* ===== Background ===== */
.bg-glow {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse 60% 50% at 20% 20%, rgba(245, 158, 11, 0.06) 0%, transparent 60%),
    radial-gradient(ellipse 50% 40% at 80% 70%, rgba(59, 130, 246, 0.04) 0%, transparent 60%),
    radial-gradient(ellipse 40% 30% at 50% 50%, rgba(139, 92, 246, 0.03) 0%, transparent 50%);
}

/* ===== Layout ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 80px 0;
  position: relative;
  z-index: 1;
}

/* ===== Navbar ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: var(--transition);
  background: transparent;
}

.navbar.scrolled {
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.navbar-logo {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  border: 1px solid var(--color-border);
  overflow: hidden;
  flex-shrink: 0;
}

.navbar-logo img { width: 100%; height: 100%; object-fit: cover; }

.navbar-title {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.navbar-title-cn {
  font-size: 20px;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.navbar-title-en {
  font-size: 9px;
  font-weight: 800;
  color: var(--color-amber);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  line-height: 1;
}

.navbar-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.navbar-nav {
  display: none;
  gap: 24px;
  list-style: none;
}

.navbar-nav a {
  font-size: 13px;
  color: var(--color-text-muted);
  transition: var(--transition);
  font-weight: 500;
}

.navbar-nav a:hover { color: var(--color-amber); }

.lang-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.03);
  transition: var(--transition);
}

.lang-toggle:hover {
  border-color: var(--color-border-hover);
  color: var(--color-amber-light);
}

.lang-toggle .active { color: var(--color-amber-light); }
.lang-toggle .sep { opacity: 0.3; }

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 100px;
  padding-bottom: 60px;
}

.hero .container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 32px;
}

.hero-content {
  flex: 1;
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  border-radius: var(--radius-pill);
  background: var(--color-amber-glow);
  border: 1px solid rgba(245, 158, 11, 0.2);
  color: var(--color-amber);
  font-size: 10px;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  font-weight: 700;
  margin-bottom: 24px;
}

.hero-badge .pulse {
  width: 7px;
  height: 7px;
  background: var(--color-amber);
  border-radius: 50%;
  animation: pulse 2s infinite;
  box-shadow: 0 0 10px var(--color-amber-glow-strong);
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(0.85); }
}

.hero-title {
  font-size: clamp(36px, 7vw, 72px);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 1.1;
  background: linear-gradient(180deg, #ffffff 0%, #e2e8f0 40%, #64748b 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 20px;
}

.hero-desc {
  font-size: clamp(15px, 2.2vw, 20px);
  color: var(--color-text-muted);
  font-weight: 300;
  letter-spacing: 0.02em;
  max-width: 540px;
  margin: 0 auto 32px;
  line-height: 1.7;
}

.hero-cta-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 36px;
  background: var(--color-amber);
  color: #000;
  font-size: 14px;
  font-weight: 700;
  border-radius: var(--radius-pill);
  transition: var(--transition);
  box-shadow: 0 0 30px var(--color-amber-glow-strong);
}

.btn-primary:hover {
  background: var(--color-amber-light);
  transform: translateY(-2px);
  box-shadow: 0 8px 40px var(--color-amber-glow-strong);
}

.btn-primary svg { width: 18px; height: 18px; }

.hero-note {
  font-size: 11px;
  color: var(--color-text-dim);
  font-family: 'SF Mono', 'Fira Code', monospace;
  max-width: 420px;
  margin: 0 auto;
  line-height: 1.7;
  opacity: 0.7;
}

.hero-card {
  display: block;
  flex-shrink: 0;
  width: min(300px, 80vw);
  padding: 6px;
  border-radius: 28px;
  background: rgba(15, 23, 42, 0.5);
  border: 1px solid var(--color-border);
  backdrop-filter: blur(20px);
  box-shadow: 0 25px 60px rgba(0, 0, 0, 0.5);
}

.hero-card-inner {
  position: relative;
  aspect-ratio: 4/5;
  border-radius: 28px;
  overflow: hidden;
}

.hero-carousel {
  position: relative;
  width: 100%;
  height: 100%;
}

.carousel-slide {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity 0.8s ease;
}

.carousel-slide.active { opacity: 1; }

.hero-card-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.6) 0%, transparent 40%);
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  padding: 20px 24px;
  z-index: 2;
}

.hero-card-overlay span {
  font-size: 13px;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.8);
  letter-spacing: 0.05em;
}

.carousel-dots {
  display: flex;
  gap: 6px;
  align-items: center;
}

.carousel-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.35);
  cursor: pointer;
  transition: all 0.3s ease;
}

.carousel-dot.active {
  background: var(--color-amber);
  width: 18px;
  border-radius: 3px;
}

/* ===== Section Headers ===== */
.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-tag {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--color-amber);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(28px, 5vw, 44px);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: #fff;
}

.section-subtitle {
  font-size: 15px;
  color: var(--color-text-muted);
  margin-top: 12px;
  max-width: 520px;
  margin-left: auto;
  margin-right: auto;
}

/* ===== Value Props ===== */
.value-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.value-card {
  padding: 32px 28px;
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  backdrop-filter: blur(12px);
  transition: var(--transition);
}

.value-card:hover {
  border-color: var(--color-border-hover);
  background: var(--color-surface-hover);
  transform: translateY(-4px);
}

.value-icon {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: var(--color-amber-glow);
  border: 1px solid rgba(245, 158, 11, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--color-amber);
}

.value-icon svg { width: 22px; height: 22px; }

.value-card h3 {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 8px;
}

.value-card p {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* ===== Features ===== */
.features { background: rgba(5, 5, 10, 0.6); }

/* Feature Tabs */
.feature-tabs {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 40px;
}

.feature-tab {
  padding: 10px 28px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.03);
  transition: var(--transition);
}

.feature-tab:hover {
  border-color: var(--color-border-hover);
  color: var(--color-amber-light);
}

.feature-tab.active {
  background: var(--color-amber-glow);
  border-color: rgba(245, 158, 11, 0.3);
  color: var(--color-amber);
}

/* LUT Grid */
.lut-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

/* LUT Card */
.lut-card {
  padding: 20px;
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  backdrop-filter: blur(12px);
  transition: var(--transition);
  display: flex;
  gap: 18px;
  align-items: flex-start;
  cursor: default;
}

.lut-card:hover {
  border-color: var(--color-border-hover);
  background: var(--color-surface-hover);
  transform: translateY(-3px);
}

.lut-card-thumb {
  width: 80px;
  height: 80px;
  border-radius: 16px;
  overflow: hidden;
  flex-shrink: 0;
  border: 1px solid var(--color-border);
  background: rgba(0, 0, 0, 0.3);
}

.lut-card-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.lut-card-info {
  flex: 1;
  min-width: 0;
}

.lut-card-name {
  font-size: 16px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 4px;
}

.lut-card-desc {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.5;
  margin-bottom: 10px;
}

.lut-card-tip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  background: rgba(245, 158, 11, 0.08);
  border: 1px solid rgba(245, 158, 11, 0.12);
  font-size: 11px;
  color: var(--color-amber);
  font-weight: 500;
  line-height: 1.4;
}

.lut-card-tip svg {
  width: 12px;
  height: 12px;
  flex-shrink: 0;
}

/* ===== Process ===== */
.process-steps {
  display: flex;
  flex-direction: column;
  gap: 24px;
  max-width: 600px;
  margin: 0 auto;
}

.process-step {
  display: flex;
  align-items: center;
  gap: 20px;
}

.step-number {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--color-amber-glow);
  border: 1px solid rgba(245, 158, 11, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 800;
  color: var(--color-amber);
  flex-shrink: 0;
}

.step-connector {
  width: 2px;
  height: 24px;
  background: linear-gradient(to bottom, rgba(245, 158, 11, 0.3), transparent);
  margin-left: 28px;
}

.process-step h4 {
  font-size: 17px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 4px;
}

.process-step p {
  font-size: 14px;
  color: var(--color-text-muted);
}

/* ===== Extension ===== */
.extension {
  background: rgba(5, 5, 10, 0.6);
}

.extension-content {
  max-width: 640px;
  margin: 0 auto;
  text-align: center;
}

.extension-details {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 32px;
}

.extension-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  font-size: 13px;
  color: var(--color-text);
  font-weight: 500;
}

.extension-chip svg { width: 16px; height: 16px; color: var(--color-amber); }

/* ===== FAQ ===== */
.faq-list {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.faq-item {
  border-radius: var(--radius-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  overflow: hidden;
  transition: var(--transition);
}

.faq-item:hover {
  border-color: var(--color-border-hover);
}

.faq-question {
  width: 100%;
  text-align: left;
  padding: 20px 24px;
  font-size: 15px;
  font-weight: 600;
  color: #fff;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--transition);
}

.faq-question:hover { color: var(--color-amber-light); }

.faq-chevron {
  width: 20px;
  height: 20px;
  color: var(--color-text-dim);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

.faq-item.open .faq-chevron { transform: rotate(180deg); }

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
}

.faq-item.open .faq-answer {
  max-height: 200px;
}

.faq-answer p {
  padding: 0 24px 20px;
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ===== Bottom CTA ===== */
.bottom-cta {
  text-align: center;
  padding: 80px 0 40px;
}

.bottom-cta .section-title { margin-bottom: 16px; }
.bottom-cta .section-subtitle { margin-bottom: 32px; }

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--color-border);
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(12px);
  padding: 32px 0;
  position: relative;
  z-index: 1;
}

.footer .container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.footer-logo {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  border: 1px solid var(--color-border);
  overflow: hidden;
}

.footer-logo img { width: 100%; height: 100%; object-fit: cover; }

.footer-title-cn {
  font-size: 15px;
  font-weight: 700;
  color: #fff;
  line-height: 1;
}

.footer-title-en {
  font-size: 8px;
  font-weight: 800;
  color: var(--color-amber);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-top: 2px;
}

.footer-copyright {
  font-size: 11px;
  color: var(--color-text-dim);
  font-family: monospace;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  font-size: 12px;
  color: var(--color-text-dim);
  transition: var(--transition);
}

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

/* ===== QR Modal ===== */
.qr-modal {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: rgba(0, 0, 0, 0.92);
  backdrop-filter: blur(24px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.qr-modal.open {
  opacity: 1;
  pointer-events: all;
}

.qr-modal-card {
  background: rgba(15, 23, 42, 0.95);
  border: 1px solid var(--color-border);
  padding: 40px;
  border-radius: 36px;
  text-align: center;
  max-width: 380px;
  width: 100%;
  transform: scale(0.92) translateY(20px);
  transition: transform 0.3s ease;
}

.qr-modal.open .qr-modal-card {
  transform: scale(1) translateY(0);
}

.qr-modal-title {
  font-size: 22px;
  font-weight: 800;
  color: #fff;
  margin-bottom: 6px;
}

.qr-modal-subtitle {
  font-size: 14px;
  color: var(--color-text-muted);
  margin-bottom: 28px;
}

.qr-code-wrapper {
  aspect-ratio: 1;
  width: 100%;
  background: #fff;
  padding: 16px;
  border-radius: 24px;
  margin-bottom: 28px;
  box-shadow: 0 0 50px rgba(245, 158, 11, 0.15);
}

.qr-code-wrapper img { width: 100%; height: 100%; object-fit: contain; }

/* WeChat in-app browser: pulsing hint on QR code */
.is-wechat .qr-code-wrapper {
  animation: wechat-pulse 2s ease-in-out infinite;
}

@keyframes wechat-pulse {
  0%, 100% { box-shadow: 0 0 50px rgba(245, 158, 11, 0.15); }
  50% { box-shadow: 0 0 50px rgba(245, 158, 11, 0.4), 0 0 80px rgba(245, 158, 11, 0.15); }
}

.btn-close-modal {
  width: 100%;
  padding: 14px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  transition: var(--transition);
}

.btn-close-modal:hover { background: rgba(255, 255, 255, 0.1); }

/* ===== Floating Mini QR ===== */
.floating-qr {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 90;
  opacity: 0;
  transform: translateY(20px) scale(0.9);
  transition: opacity 0.4s ease, transform 0.4s ease;
  pointer-events: none;
}

.floating-qr.visible {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: all;
}

.floating-qr-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 12px;
  background: rgba(15, 15, 25, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5), 0 0 20px rgba(245, 158, 11, 0.1);
  cursor: pointer;
  transition: var(--transition);
}

.floating-qr-card:hover {
  border-color: var(--color-border-hover);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5), 0 0 30px rgba(245, 158, 11, 0.2);
  transform: translateY(-3px);
}

.floating-qr-card img {
  width: 100px;
  height: 100px;
  border-radius: 12px;
  background: #fff;
  padding: 4px;
}

.floating-qr-card span {
  font-size: 10px;
  font-weight: 600;
  color: var(--color-amber);
  letter-spacing: 0.05em;
}

@media (max-width: 639px) {
  .floating-qr { bottom: 16px; right: 16px; }
  .floating-qr-card img { width: 80px; height: 80px; }
}

/* ===== Scroll Reveal ===== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }

/* ===== Responsive ===== */
@media (max-width: 1023px) {
  /* Mobile hero: image first, one-line intro + CTA only */
  .hero { min-height: auto; padding-top: 80px; padding-bottom: 40px; }
  .hero .container { gap: 24px; }
  .hero-badge { display: none; }
  .hero-title { display: none; }
  .hero-note { display: none; }
  .hero-card { order: -1; }
  .hero-badge { display: inline-flex; order: -2; margin-bottom: 12px; }
  .hero-desc {
    font-size: 14px;
    margin-bottom: 16px;
    max-width: 320px;
  }
}

@media (max-width: 639px) {
  .lut-grid { grid-template-columns: 1fr; }
  .lut-card-thumb { width: 64px; height: 64px; border-radius: 12px; }
}

@media (min-width: 640px) {
  .value-grid { grid-template-columns: repeat(3, 1fr); }
  .process-steps { flex-direction: row; gap: 0; }
  .process-step { flex-direction: column; text-align: center; flex: 1; }
  .step-connector { display: none; }
}

@media (min-width: 1024px) {
  .navbar-nav { display: flex; }

  .hero .container { flex-direction: row; gap: 60px; }
  .hero-content { text-align: left; }
  .hero-desc { margin: 0 0 32px; }
  .hero-cta-group { align-items: flex-start; }
  .hero-note { margin: 0; }
  .hero-card { width: 360px; padding: 8px; border-radius: 36px; }

  .lut-grid { grid-template-columns: repeat(2, 1fr); }

  .footer .container {
    flex-direction: row;
    justify-content: space-between;
  }
}