:root {
  --bg: #0c0c0e;
  --bg-elevated: #141416;
  --bg-card: rgba(28, 28, 32, 0.72);
  --text: #fafafa;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --accent: #a78bfa;
  --accent-strong: #8b5cf6;
  --accent-deep: #7c3aed;
  --border: rgba(255, 255, 255, 0.08);
  --glow: rgba(139, 92, 246, 0.35);
  --radius: 14px;
  --font: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC',
    'Microsoft YaHei', sans-serif;
  --mono: 'SF Mono', Menlo, Consolas, monospace;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

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

a:hover {
  color: var(--accent-light, #c4b5fd);
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0.5rem;
  padding: 0.5rem 1rem;
  background: var(--accent-deep);
  color: white;
  border-radius: 8px;
  z-index: 100;
}

.skip-link:focus {
  left: 0.5rem;
}

/* Ambient background */
.page-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(124, 58, 237, 0.22), transparent),
    radial-gradient(ellipse 60% 40% at 100% 50%, rgba(139, 92, 246, 0.12), transparent),
    radial-gradient(ellipse 50% 35% at 0% 80%, rgba(167, 139, 250, 0.1), transparent),
    var(--bg);
}

.wrap {
  position: relative;
  z-index: 1;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(12, 12, 14, 0.75);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  row-gap: 0.6rem;
  column-gap: 1rem;
  min-height: 64px;
  height: auto;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0.55rem 1.5rem;
  box-sizing: border-box;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  flex: 0 0 auto;
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
  color: var(--text);
}

.brand img {
  width: 32px;
  height: 32px;
}

.nav-main {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.45rem 1.2rem;
  flex: 1 1 auto;
  min-width: 0;
}

.nav-main a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
}

.nav-main a:hover {
  color: var(--text);
}

.header-tools {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.65rem 0.85rem;
  justify-content: flex-end;
  flex: 0 1 auto;
  min-width: 0;
}

@media (min-width: 769px) {
  .header-tools {
    padding-left: 1rem;
    margin-left: 0.35rem;
    border-left: 1px solid var(--border);
  }
}

.header-share-link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  white-space: nowrap;
}

.header-share-link:hover {
  color: var(--text);
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 0.2rem;
  padding: 2px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.03);
}

.lang-btn {
  padding: 0.32rem 0.55rem;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  border-radius: 8px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  font-family: inherit;
  line-height: 1.2;
  transition: color 0.15s ease, background 0.15s ease;
}

.lang-btn:hover:not(.lang-btn--active) {
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.05);
}

.lang-btn--active {
  color: var(--text);
  background: rgba(139, 92, 246, 0.22);
  box-shadow: 0 0 0 1px rgba(139, 92, 246, 0.35);
}

.menu-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.45rem 0.65rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.85rem;
}

@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }

  .nav-main {
    display: none;
  }

  .site-header.nav-open .nav-main {
    display: flex;
  }

  .header-tools {
    margin-left: auto;
    padding-left: 0;
    border-left: none;
  }

  .site-header.nav-open .header-inner {
    flex-wrap: wrap;
    height: auto;
    padding-bottom: 1rem;
    gap: 1rem;
  }

  .site-header.nav-open .nav-main {
    flex-direction: column;
    width: 100%;
    align-items: flex-start;
    gap: 0.75rem;
  }

  .site-header.nav-open .header-tools {
    width: 100%;
    justify-content: flex-start;
    margin-left: 0;
  }

  .site-header.nav-open .lang-switch {
    width: 100%;
    justify-content: center;
    margin-bottom: 0.25rem;
  }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.55rem 1.15rem;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: 10px;
  border: none;
  cursor: pointer;
  font-family: inherit;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-strong), var(--accent-deep));
  color: white;
  box-shadow: 0 4px 24px var(--glow);
}

.btn-primary:hover {
  box-shadow: 0 6px 32px var(--glow);
  filter: brightness(1.05);
}

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

.btn-ghost:hover {
  color: var(--text);
  border-color: rgba(255, 255, 255, 0.18);
  background: rgba(255, 255, 255, 0.04);
}

.btn-soon:disabled {
  cursor: not-allowed;
  opacity: 0.65;
}

/* Hero */
.hero {
  padding: 4.5rem 0 5rem;
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.85rem;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--accent);
  background: rgba(139, 92, 246, 0.12);
  border: 1px solid rgba(139, 92, 246, 0.25);
  border-radius: 999px;
  margin-bottom: 1.5rem;
}

.hero-tagline {
  font-size: 1.2rem;
  color: var(--text-secondary);
  max-width: 40rem;
  margin: 0 auto 2rem;
  line-height: 1.65;
}

.hero-tagline strong {
  color: var(--text);
  font-weight: 600;
}

.hero-free {
  font-size: 0.95rem;
  color: var(--text-secondary);
  max-width: 40rem;
  margin: 0 auto 1.75rem;
  line-height: 1.6;
  text-align: center;
}

.hero-free strong {
  color: #86efac;
  font-weight: 700;
}

.hero-points {
  list-style: none;
  margin: 0 auto 2rem;
  padding: 0;
  max-width: 44rem;
  display: grid;
  gap: 1rem;
  text-align: left;
}

@media (min-width: 720px) {
  .hero-points {
    grid-template-columns: 1fr 1fr 1fr;
    gap: 1.25rem;
  }
}

.hero-points li {
  margin: 0;
  padding: 1rem 1.1rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.03);
  transition: border-color 0.2s ease, background 0.2s ease;
}

.hero-points li:hover {
  border-color: rgba(139, 92, 246, 0.35);
  background: rgba(139, 92, 246, 0.06);
}

.hero-point-title {
  display: block;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text);
  margin-bottom: 0.35rem;
  letter-spacing: -0.02em;
}

.hero-point-desc {
  display: block;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.hero h1 {
  font-size: clamp(2.25rem, 5vw, 3.25rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin: 0 0 1rem;
  background: linear-gradient(180deg, #fff 0%, #e4e4e7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
  margin-bottom: 1.25rem;
}

.hero-note {
  font-size: 0.85rem;
  color: var(--text-muted);
  max-width: 36rem;
  margin: 0 auto 2.5rem;
}

.hero-visual {
  position: relative;
  max-width: 920px;
  margin: 0 auto;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  overflow: hidden;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.45);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.hero-visual-inner {
  aspect-ratio: 16 / 9;
  min-height: 220px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  padding: 2rem 1.5rem 1.75rem;
  background:
    linear-gradient(145deg, rgba(124, 58, 237, 0.08) 0%, transparent 50%),
    repeating-linear-gradient(
      -12deg,
      transparent,
      transparent 40px,
      rgba(255, 255, 255, 0.02) 40px,
      rgba(255, 255, 255, 0.02) 41px
    );
}

.hero-visual-inner--demo {
  padding: 1.25rem 1.25rem 1.1rem;
  gap: 0.65rem;
  align-items: stretch;
  justify-content: flex-start;
}

.hero-demo-caption {
  margin: 0;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-align: center;
  letter-spacing: 0.02em;
  min-height: 1.35em;
  transition: color 0.35s ease;
}

.hero-demo-caption[data-step='2'],
.hero-demo-caption[data-step='3'] {
  color: var(--accent);
}

.hero-app-embed {
  width: 100%;
  flex: 1;
  min-height: 0;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.1);
  background: #141414;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.06);
}

.hero-app-iframe {
  display: block;
  width: 100%;
  height: min(52vh, 520px);
  min-height: 320px;
  border: 0;
  background: var(--bg-primary);
}

@media (max-width: 640px) {
  .hero-demo-caption {
    font-size: 0.75rem;
  }

  .hero-app-iframe {
    min-height: 260px;
    height: min(48vh, 420px);
  }
}

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

.section-head {
  margin-bottom: 2rem;
}

.section-title {
  font-size: clamp(1.5rem, 3.5vw, 1.85rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  text-align: center;
  margin: 0 0 0.5rem;
}

.section-sub {
  text-align: center;
  color: var(--text-secondary);
  max-width: 32rem;
  margin: 0 auto;
  font-size: 1rem;
  line-height: 1.6;
}

.section-sub--wide {
  max-width: 40rem;
}

/* Core pillars */
.pillars {
  padding-top: 3rem;
}

.pillar-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.15rem;
}

@media (min-width: 720px) {
  .pillar-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
  }
}

.pillar-card {
  position: relative;
  padding: 1.5rem 1.5rem 1.45rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  overflow: hidden;
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.pillar-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.35);
}

.pillar-card--accent {
  border-color: rgba(139, 92, 246, 0.35);
  background:
    linear-gradient(155deg, rgba(124, 58, 237, 0.14) 0%, rgba(20, 20, 22, 0.92) 42%),
    var(--bg-elevated);
}

.pillar-card--accent::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-strong), var(--accent-deep));
  opacity: 0.9;
}

.pillar-index {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--accent);
  margin-bottom: 0.65rem;
  opacity: 0.9;
}

.pillar-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}

.pillar-lead {
  margin: 0 0 0.85rem;
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

.pillar-lead strong {
  color: var(--text);
  font-weight: 600;
}

.pillar-list {
  margin: 0;
  padding: 0 0 0 1.15rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.55;
}

.pillar-list li {
  margin-bottom: 0.45rem;
}

.pillar-list li:last-child {
  margin-bottom: 0;
}

.pillar-list strong {
  color: var(--text);
  font-weight: 600;
}

.pillar-card:target {
  box-shadow: 0 0 0 2px rgba(139, 92, 246, 0.55), 0 20px 50px rgba(0, 0, 0, 0.4);
}

.features-section {
  padding-top: 3.5rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.25rem;
}

.feature-grid--compact .feature-card h3 {
  font-size: 1.02rem;
}

.feature-grid--compact .feature-card p {
  font-size: 0.9rem;
}

.feature-card {
  padding: 1.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
  backdrop-filter: blur(8px);
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.feature-card:hover {
  border-color: rgba(139, 92, 246, 0.35);
  transform: translateY(-2px);
}

.feature-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: rgba(139, 92, 246, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--accent);
  margin-bottom: 1rem;
}

.feature-card h3 {
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
  font-weight: 600;
}

.feature-card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.55;
}

/* Pill list */
.pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
  margin-top: 2rem;
}

.pill {
  padding: 0.4rem 0.9rem;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: 999px;
}

.pill--free {
  color: #bbf7d0;
  border-color: rgba(74, 222, 128, 0.35);
  background: rgba(74, 222, 128, 0.1);
  font-weight: 600;
}

/* Audience */
.audience {
  background: linear-gradient(180deg, transparent, rgba(124, 58, 237, 0.06), transparent);
}

.audience-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}

.audience-item {
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-elevated);
}

.audience-item strong {
  display: block;
  margin-bottom: 0.35rem;
  font-size: 1rem;
}

.audience-item span {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* 锚点跳转：预留顶栏并略上移，避免标题被挡或落点偏低 */
#pillars,
#audience,
#cta {
  scroll-margin-top: calc(4.5rem - 0.85rem);
}

/* CTA band */
.cta-band {
  text-align: center;
  padding: 3.5rem 2rem;
  border-radius: var(--radius);
  border: 1px solid rgba(139, 92, 246, 0.3);
  background: linear-gradient(135deg, rgba(124, 58, 237, 0.18), rgba(12, 12, 14, 0.9));
  margin: 2rem 0 4rem;
}

.cta-band h2 {
  font-size: 1.5rem;
  margin: 0 0 0.75rem;
}

.cta-band p {
  color: var(--text-secondary);
  margin: 0 0 1.5rem;
  max-width: 28rem;
  margin-left: auto;
  margin-right: auto;
}

/* Footer */
.site-footer {
  position: relative;
  z-index: 2;
  border-top: 1px solid var(--border);
  padding: 2rem 0 2.5rem;
  color: var(--text-muted);
  font-size: 0.875rem;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.footer-inner--stack {
  flex-basis: 100%;
  align-items: flex-start;
  justify-content: flex-start;
  padding-bottom: 1.75rem;
  margin-bottom: 0.25rem;
  border-bottom: 1px solid var(--border);
}

.share-block {
  width: 100%;
}

.share-title {
  margin: 0 0 0.35rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.share-hint {
  margin: 0 0 1rem;
  max-width: 42rem;
  font-size: 0.8125rem;
  line-height: 1.55;
  color: var(--text-muted);
}

.share-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
}

.share-row--footer {
  gap: 0.5rem 0.45rem;
}

a.share-btn,
button.share-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.45rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.03);
  font-size: 0.8125rem;
  font-family: inherit;
  line-height: 1.25;
  cursor: pointer;
  color: var(--text-secondary);
  text-decoration: none;
  transition:
    border-color 0.15s ease,
    color 0.15s ease,
    background 0.15s ease;
}

a.share-btn:hover,
button.share-btn:hover {
  border-color: rgba(167, 139, 250, 0.45);
  color: var(--text);
  background: rgba(139, 92, 246, 0.08);
}

button.share-btn {
  appearance: none;
}

.share-toast {
  position: fixed;
  bottom: 1.35rem;
  left: 50%;
  z-index: 200;
  max-width: calc(100vw - 2rem);
  padding: 0.55rem 1.1rem;
  font-size: 0.875rem;
  line-height: 1.35;
  color: var(--text);
  text-align: center;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
  transform: translateX(-50%);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition:
    opacity 0.2s ease,
    visibility 0.2s ease;
}

.share-toast.share-toast--show {
  opacity: 1;
  visibility: visible;
}

.footer-links {
  display: flex;
  gap: 1.25rem;
}

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

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

code {
  font-family: var(--mono);
  font-size: 0.88em;
  padding: 0.15em 0.4em;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 6px;
}