/* WeChatDedup marketing site */
:root {
  --bg: #f6f8fa;
  --bg-elev: #ffffff;
  --ink: #0f172a;
  --muted: #64748b;
  --line: #e2e8f0;
  --brand: #0f766e;
  --brand-dark: #0d5f59;
  --brand-soft: #ccfbf1;
  --brand-glow: rgba(15, 118, 110, 0.14);
  --accent: #0891b2;
  --warn-bg: #fff7ed;
  --warn-ink: #9a3412;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 1px 2px rgba(15, 23, 42, 0.04), 0 12px 32px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 20px 50px rgba(15, 23, 42, 0.1);
  --font: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    system-ui, -apple-system, sans-serif;
  --mono: ui-monospace, "Cascadia Code", "SF Mono", Menlo, Consolas, monospace;
  --max: 1080px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--brand);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  width: min(100% - 2rem, var(--max));
  margin-inline: auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: rgba(246, 248, 250, 0.85);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

.site-header.scrolled {
  border-bottom-color: var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--ink);
  text-decoration: none;
}

.logo:hover {
  text-decoration: none;
}

.logo-mark {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: linear-gradient(145deg, var(--brand), var(--accent));
  display: grid;
  place-items: center;
  color: #fff;
  box-shadow: 0 6px 16px var(--brand-glow);
}

.logo-mark svg {
  width: 18px;
  height: 18px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav a {
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 500;
  padding: 0.45rem 0.75rem;
  border-radius: 8px;
  text-decoration: none;
}

.nav a:hover {
  color: var(--ink);
  background: rgba(15, 23, 42, 0.04);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.7rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.15s, box-shadow 0.15s, background 0.15s;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--brand);
  color: #fff;
  box-shadow: 0 8px 20px var(--brand-glow);
}

.btn-primary:hover {
  background: var(--brand-dark);
  color: #fff;
}

.btn-ghost {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}

.btn-ghost:hover {
  background: var(--bg-elev);
  border-color: #cbd5e1;
}

.btn-sm {
  padding: 0.45rem 0.9rem;
  font-size: 0.85rem;
}

.lang-btn {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  color: var(--muted);
  border-radius: 999px;
  padding: 0.4rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
}

.lang-btn:hover {
  color: var(--ink);
  border-color: #cbd5e1;
}

.nav-burger {
  display: none;
  width: 40px;
  height: 40px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--bg-elev);
  cursor: pointer;
  padding: 0;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
}

.nav-burger span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
  border-radius: 1px;
  transition: transform 0.2s, opacity 0.2s;
}

.nav-burger.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-burger.open span:nth-child(2) {
  opacity: 0;
}
.nav-burger.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Hero */
.hero {
  padding: 3.5rem 0 4rem;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: -20% 20% auto -10%;
  height: 420px;
  background: radial-gradient(ellipse, var(--brand-glow), transparent 70%);
  pointer-events: none;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 2.5rem;
  align-items: center;
  position: relative;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  background: var(--brand-soft);
  color: var(--brand-dark);
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.hero h1 {
  font-size: clamp(1.85rem, 4vw, 2.65rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 0 0 1rem;
}

.hero-pitch {
  font-size: 1.1rem;
  color: var(--muted);
  max-width: 36rem;
  margin: 0 0 1.75rem;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.hero-note {
  font-size: 0.85rem;
  color: var(--muted);
}

.hero-card {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 4px);
  box-shadow: var(--shadow-lg);
  padding: 1.5rem;
  position: relative;
}

.hero-card-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
}

.hero-card-top .dots {
  display: flex;
  gap: 6px;
}

.hero-card-top .dots i {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: #e2e8f0;
}

.hero-card-top .dots i:nth-child(1) {
  background: #fca5a5;
}
.hero-card-top .dots i:nth-child(2) {
  background: #fcd34d;
}
.hero-card-top .dots i:nth-child(3) {
  background: #86efac;
}

.version-pill {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--brand);
  background: var(--brand-soft);
  padding: 0.2rem 0.55rem;
  border-radius: 6px;
  font-weight: 600;
}

.mock-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.stat {
  background: var(--bg);
  border-radius: var(--radius-sm);
  padding: 0.85rem 0.75rem;
  text-align: center;
}

.stat strong {
  display: block;
  font-size: 1.15rem;
  color: var(--brand);
  letter-spacing: -0.02em;
}

.stat span {
  font-size: 0.72rem;
  color: var(--muted);
}

.mock-bars {
  display: flex;
  align-items: flex-end;
  gap: 8px;
  height: 88px;
  padding: 0.5rem 0.25rem 0;
  margin-bottom: 1.25rem;
}

.mock-bars span {
  flex: 1;
  border-radius: 6px 6px 2px 2px;
  background: linear-gradient(180deg, var(--brand), #5eead4);
  opacity: 0.85;
}

.mock-bars span:nth-child(1) { height: 42%; }
.mock-bars span:nth-child(2) { height: 68%; }
.mock-bars span:nth-child(3) { height: 55%; }
.mock-bars span:nth-child(4) { height: 90%; }
.mock-bars span:nth-child(5) { height: 35%; }
.mock-bars span:nth-child(6) { height: 72%; }
.mock-bars span:nth-child(7) { height: 48%; }

.share-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

.share-row img {
  width: 72px;
  height: 72px;
  border-radius: 8px;
  border: 1px solid var(--line);
}

.share-row p {
  margin: 0;
  font-size: 0.85rem;
}

.share-row p strong {
  display: block;
  margin-bottom: 0.15rem;
}

.share-row p span {
  color: var(--muted);
  font-size: 0.78rem;
}

/* Sections */
section {
  padding: 4rem 0;
}

.section-head {
  text-align: center;
  max-width: 36rem;
  margin: 0 auto 2.5rem;
}

.section-head h2 {
  font-size: clamp(1.5rem, 3vw, 1.9rem);
  letter-spacing: -0.02em;
  margin: 0 0 0.6rem;
}

.section-head p {
  margin: 0;
  color: var(--muted);
}

/* Steps */
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

.step {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.35rem 1.2rem;
  box-shadow: var(--shadow);
  position: relative;
}

.step-num {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  background: var(--brand-soft);
  color: var(--brand-dark);
  font-weight: 700;
  font-size: 0.9rem;
  display: grid;
  place-items: center;
  margin-bottom: 0.9rem;
}

.step h3 {
  margin: 0 0 0.5rem;
  font-size: 1rem;
}

.step p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--muted);
}

/* Features */
.features-bg {
  background: linear-gradient(180deg, #eef2f6 0%, var(--bg) 100%);
}

.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.feature {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.4rem 1.25rem;
  box-shadow: var(--shadow);
}

.feature-icon {
  width: 40px;
  height: 40px;
  border-radius: 11px;
  background: var(--brand-soft);
  color: var(--brand);
  display: grid;
  place-items: center;
  margin-bottom: 0.9rem;
}

.feature-icon svg {
  width: 20px;
  height: 20px;
}

.feature h3 {
  margin: 0 0 0.45rem;
  font-size: 1.02rem;
}

.feature p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--muted);
}

/* Download */
.download-panel {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 6px);
  box-shadow: var(--shadow);
  padding: 2rem;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 2rem;
  align-items: center;
}

.dl-info h2 {
  margin: 0 0 0.4rem;
  font-size: 1.55rem;
}

.dl-info > p {
  margin: 0 0 1.25rem;
  color: var(--muted);
}

.dl-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 0.85rem;
}

.dl-meta {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--muted);
}

.dl-hint {
  font-size: 0.85rem;
  color: var(--muted);
  margin: 0 0 0.75rem;
}

.dl-warn {
  display: flex;
  gap: 0.5rem;
  align-items: flex-start;
  background: var(--warn-bg);
  color: var(--warn-ink);
  border-radius: var(--radius-sm);
  padding: 0.75rem 0.9rem;
  font-size: 0.85rem;
  margin: 0;
}

.dl-side {
  text-align: center;
  padding: 1rem 1.25rem;
  background: var(--bg);
  border-radius: var(--radius);
  border: 1px dashed #cbd5e1;
}

.dl-side img {
  width: 120px;
  height: 120px;
  margin: 0 auto 0.75rem;
  border-radius: 10px;
  background: #fff;
}

.dl-side p {
  margin: 0;
  font-size: 0.8rem;
  color: var(--muted);
}

.dl-side code {
  font-family: var(--mono);
  font-size: 0.72rem;
  word-break: break-all;
}

/* FAQ */
.faq {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.faq details {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 0.15rem 1rem;
  box-shadow: var(--shadow);
}

.faq summary {
  cursor: pointer;
  font-weight: 600;
  padding: 0.9rem 0;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::after {
  content: "+";
  font-weight: 400;
  color: var(--muted);
  font-size: 1.2rem;
  flex-shrink: 0;
}

.faq details[open] summary::after {
  content: "–";
}

.faq details p {
  margin: 0 0 1rem;
  color: var(--muted);
  font-size: 0.92rem;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 2rem 0 2.5rem;
  color: var(--muted);
  font-size: 0.88rem;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
  align-items: flex-start;
}

.footer-brand {
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 0.35rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

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

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

/* Responsive */
@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }

  .steps {
    grid-template-columns: 1fr 1fr;
  }

  .features {
    grid-template-columns: 1fr 1fr;
  }

  .download-panel {
    grid-template-columns: 1fr;
  }

  .dl-side {
    justify-self: center;
    width: 100%;
    max-width: 280px;
  }
}

@media (max-width: 680px) {
  .nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background: rgba(255, 255, 255, 0.98);
    border-bottom: 1px solid var(--line);
    padding: 0.75rem 1rem 1rem;
    gap: 0.15rem;
  }

  .nav.open {
    display: flex;
  }

  .nav a {
    padding: 0.75rem 0.85rem;
  }

  .nav-burger {
    display: inline-flex;
  }

  .header-cta-desktop {
    display: none;
  }

  .steps,
  .features {
    grid-template-columns: 1fr;
  }

  .mock-stats {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 2rem;
  }
}