:root {
  --bg: #faf8f5;
  --bg-elev: #ffffff;
  --bg-muted: #f3f0eb;
  --text: #1c1917;
  --text-muted: #57534e;
  --text-faint: #78716c;
  --border: rgba(28, 25, 23, 0.08);
  --clay: #0d9488;
  --clay-soft: rgba(13, 148, 136, 0.12);
  --warm: #d97706;
  --accent: #0284c7;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 24px 60px -28px rgba(15, 23, 42, 0.28);
  --font-ui: "Inter", system-ui, "Segoe UI", sans-serif;
  --font-serif: "Source Serif 4", "Noto Serif SC", Georgia, serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;
  --max: 1120px;
  --nav-h: 64px;
}

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

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

body {
  margin: 0;
  font-family: var(--font-ui);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }

.container {
  width: min(var(--max), calc(100% - 48px));
  margin-inline: auto;
}

/* ---------- Nav ---------- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--nav-h);
  background: rgba(250, 248, 245, 0.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}

.site-nav .container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.brand img { width: 28px; height: 28px; border-radius: 8px; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a {
  padding: 8px 12px;
  font-size: 14px;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  transition: color 0.15s, background 0.15s;
}

.nav-links a:hover {
  color: var(--text);
  background: var(--bg-muted);
}

.nav-cta {
  display: flex;
  gap: 8px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  font: inherit;
  font-size: 14px;
  font-weight: 500;
  border-radius: 999px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, background 0.15s;
}

.btn:hover { transform: translateY(-1px); }

.btn-primary {
  background: var(--text);
  color: #fff;
  box-shadow: 0 10px 24px -12px rgba(0, 0, 0, 0.45);
}

.btn-primary:hover { background: #292524; }

.btn-secondary {
  background: var(--bg-elev);
  border-color: var(--border);
  color: var(--text);
}

.btn-secondary:hover { background: var(--bg-muted); }

/* ---------- Hero ---------- */
.hero {
  padding: 72px 0 48px;
  text-align: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  margin-bottom: 24px;
  font-size: 13px;
  font-weight: 500;
  color: var(--clay);
  background: var(--clay-soft);
  border-radius: 999px;
}

.hero h1 {
  margin: 0 0 16px;
  font-family: var(--font-serif);
  font-size: clamp(2.4rem, 5vw, 3.75rem);
  font-weight: 500;
  line-height: 1.08;
  letter-spacing: -0.03em;
}

.hero .lead {
  max-width: 640px;
  margin: 0 auto 32px;
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--text-muted);
  line-height: 1.55;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-bottom: 56px;
}

.hero-visual {
  position: relative;
  max-width: 960px;
  margin: 0 auto;
  border-radius: calc(var(--radius) + 4px);
  overflow: hidden;
  border: 1px solid var(--border);
  background: linear-gradient(145deg, #fff 0%, #f8fafc 55%, #eff6ff 100%);
  box-shadow: var(--shadow);
  aspect-ratio: 16 / 9;
}

.hero-mock {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-columns: 220px 1fr 280px;
  font-size: 12px;
}

.mock-sidebar {
  background: #f1f5f9;
  border-right: 1px solid var(--border);
  padding: 16px 12px;
}

.mock-sidebar .mock-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
  font-weight: 600;
}

.mock-sidebar .mock-logo img { width: 20px; height: 20px; border-radius: 6px; }

.mock-nav-item {
  padding: 8px 10px;
  margin-bottom: 4px;
  border-radius: 8px;
  color: var(--text-muted);
}

.mock-nav-item.active {
  background: #fff;
  color: var(--text);
  font-weight: 500;
}

.mock-chat {
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.mock-bubble {
  max-width: 85%;
  padding: 12px 14px;
  border-radius: 14px;
  line-height: 1.5;
}

.mock-bubble.user {
  align-self: flex-end;
  background: var(--clay-soft);
  color: var(--text);
}

.mock-bubble.assistant {
  align-self: flex-start;
  background: #fff;
  border: 1px solid var(--border);
}

.mock-artifacts {
  background: #fafafa;
  border-left: 1px solid var(--border);
  padding: 16px;
}

.mock-artifacts h4 {
  margin: 0 0 12px;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-faint);
}

.mock-chip {
  padding: 10px 12px;
  margin-bottom: 8px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
}

.mock-chip strong { display: block; font-size: 12px; margin-bottom: 2px; }
.mock-chip span { font-size: 11px; color: var(--text-faint); }

/* ---------- Sections ---------- */
section { padding: 88px 0; }

.section-label {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.section-label .idx {
  font-family: var(--font-mono);
  color: var(--warm);
}

.section-head {
  max-width: 720px;
  margin-bottom: 56px;
}

.section-head h2 {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.section-head p {
  margin: 0;
  font-size: 1.05rem;
  color: var(--text-muted);
}

.feature-grid {
  display: grid;
  gap: 24px;
}

.feature-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
  padding: 36px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 4px);
}

.feature-card.reverse { direction: rtl; }
.feature-card.reverse > * { direction: ltr; }

.feature-card h3 {
  margin: 0 0 10px;
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 500;
  letter-spacing: -0.02em;
}

.feature-card p {
  margin: 0;
  color: var(--text-muted);
  line-height: 1.65;
}

.feature-visual {
  min-height: 220px;
  padding: 24px;
  border-radius: var(--radius);
  background: linear-gradient(160deg, #f8fafc, #ecfeff);
  border: 1px solid var(--border);
}

.feature-visual pre {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: #334155;
  white-space: pre-wrap;
}

.feature-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 32px;
}

.feature-list-item {
  padding: 24px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.feature-list-item h4 {
  margin: 0 0 8px;
  font-size: 1rem;
  font-weight: 600;
}

.feature-list-item p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-muted);
}

/* ---------- Use cases tabs ---------- */
.usecases {
  background: var(--bg-muted);
  border-block: 1px solid var(--border);
}

.tab-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 32px;
}

.tab-btn {
  padding: 10px 16px;
  font: inherit;
  font-size: 14px;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.15s;
}

.tab-btn:hover { color: var(--text); background: rgba(255,255,255,0.6); }

.tab-btn.active {
  color: var(--text);
  background: #fff;
  border-color: var(--border);
  box-shadow: 0 4px 16px -8px rgba(0,0,0,0.15);
}

.tab-panel {
  display: none;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
  padding: 36px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 4px);
}

.tab-panel.active { display: grid; }

.tab-panel h3 {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-size: 1.6rem;
  font-weight: 500;
}

.tab-panel p {
  margin: 0 0 16px;
  color: var(--text-muted);
  line-height: 1.65;
}

.tab-panel ul {
  margin: 0;
  padding-left: 18px;
  color: var(--text-muted);
}

.tab-panel li { margin-bottom: 6px; }

.prompt-mock {
  padding: 20px;
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 13px;
}

.prompt-mock .label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-faint);
  margin-bottom: 8px;
}

/* ---------- Demos ---------- */
.demo-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.demo-card {
  padding: 28px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: box-shadow 0.2s, transform 0.2s;
}

.demo-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.demo-card h4 {
  margin: 0 0 8px;
  font-size: 1.1rem;
}

.demo-card p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-muted);
}

/* ---------- Stack ---------- */
.stack-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.stack-item {
  padding: 20px 16px;
  text-align: center;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
}

.stack-item span {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  font-weight: 400;
  color: var(--text-faint);
}

/* ---------- FAQ ---------- */
.faq-list {
  max-width: 760px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.faq-item {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.faq-q {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 20px;
  font: inherit;
  font-size: 1rem;
  font-weight: 500;
  text-align: left;
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--text);
}

.faq-q svg {
  flex-shrink: 0;
  transition: transform 0.2s;
}

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

.faq-a {
  display: none;
  padding: 0 20px 18px;
  color: var(--text-muted);
  line-height: 1.65;
}

.faq-item.open .faq-a { display: block; }

/* ---------- Footer ---------- */
.site-footer {
  padding: 48px 0;
  border-top: 1px solid var(--border);
  background: #fff;
}

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

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  font-size: 14px;
  color: var(--text-muted);
}

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

.footer-copy {
  font-size: 13px;
  color: var(--text-faint);
}

.btn-label-short { display: none; }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero-mock { grid-template-columns: 1fr; }
  .mock-sidebar, .mock-artifacts { display: none; }
  .feature-card, .feature-card.reverse { grid-template-columns: 1fr; direction: ltr; }
  .feature-list { grid-template-columns: 1fr; }
  .tab-panel { grid-template-columns: 1fr; }
  .demo-grid { grid-template-columns: 1fr; }
  .stack-grid { grid-template-columns: repeat(2, 1fr); }
  .nav-links { display: none; }
  .nav-cta .btn-secondary { display: none; }
}

@media (max-width: 560px) {
  :root { --nav-h: 56px; }

  .container {
    width: calc(100% - 32px);
    padding-inline: max(0px, env(safe-area-inset-left)) max(0px, env(safe-area-inset-right));
  }

  body { overflow-x: hidden; }

  .site-nav .container { gap: 12px; }
  .brand { min-width: 0; }
  .brand-name { display: none; }
  .nav-cta .btn {
    min-height: 44px;
    padding: 10px 16px;
    font-size: 14px;
  }
  .btn-label-full { display: none; }
  .btn-label-short { display: inline; }

  .hero { padding: 36px 0 28px; }
  .eyebrow { font-size: 12px; margin-bottom: 16px; }
  .hero h1 {
    font-size: clamp(1.75rem, 7.5vw, 2.25rem);
    line-height: 1.12;
  }
  .hero .lead {
    font-size: 1rem;
    color: var(--text);
    line-height: 1.65;
    margin-bottom: 24px;
  }
  .hero-actions {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
    margin-bottom: 32px;
  }
  .hero-actions .btn {
    width: 100%;
    min-height: 48px;
    font-size: 15px;
  }

  .hero-visual {
    aspect-ratio: auto;
    min-height: 180px;
    border-radius: var(--radius);
  }
  .mock-chat { padding: 16px; gap: 12px; }
  .mock-bubble {
    max-width: 92%;
    padding: 10px 12px;
    font-size: 13px;
    line-height: 1.55;
  }

  section { padding: 56px 0; }
  .section-head { margin-bottom: 32px; }
  .section-head h2 { font-size: clamp(1.5rem, 5vw, 1.85rem); }
  .section-head p { font-size: 0.975rem; }

  .feature-card { padding: 22px 18px; gap: 20px; }
  .feature-card h3 { font-size: 1.25rem; }
  .feature-visual { min-height: 140px; padding: 16px; }
  .feature-visual pre { font-size: 11px; }
  .feature-list-item { padding: 20px; }

  .tab-bar {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    margin-inline: -4px;
    padding-inline: 4px 16px;
    margin-bottom: 20px;
  }
  .tab-bar::-webkit-scrollbar { display: none; }
  .tab-btn {
    flex-shrink: 0;
    white-space: nowrap;
    font-size: 13px;
    padding: 10px 14px;
  }
  .tab-panel { padding: 22px 18px; gap: 20px; }
  .tab-panel h3 { font-size: 1.3rem; }

  .demo-card { padding: 20px; }
  .stack-grid { grid-template-columns: 1fr; }

  .faq-q {
    padding: 16px;
    font-size: 0.95rem;
    gap: 12px;
  }
  .faq-a { padding: 0 16px 16px; font-size: 0.925rem; }

  .site-footer { padding: 36px 0; }
  .footer-inner {
    flex-direction: column;
    text-align: center;
    gap: 16px;
  }
  .footer-links { justify-content: center; gap: 16px; }
}