/* ===== Theme tokens (frozen) ===== */
:root {
  --color-bg: #ffffff;
  --color-bg-alt: #faf9fc;
  --color-text: #1a1523;
  --color-muted: #6b6575;
  --color-border: #ece9f2;

  --color-accent: #7c3aed;
  --color-accent-dark: #6423d0;
  --color-accent-light: #f3edfe;

  --font-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;

  --shadow-sm: 0 1px 2px rgba(26, 21, 35, 0.06);
  --shadow-md: 0 8px 24px rgba(124, 58, 237, 0.10);

  --max-width: 1120px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-base);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

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

a { color: inherit; text-decoration: none; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.logo .dot { color: var(--color-accent); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-muted);
  transition: color 0.15s ease;
}

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

.nav-cta {
  padding: 9px 18px;
  border-radius: var(--radius-sm);
  background: var(--color-accent);
  color: #fff !important;
  font-weight: 600;
  font-size: 0.9rem;
  transition: background 0.15s ease;
}

.nav-cta:hover { background: var(--color-accent-dark); }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  margin: 5px 0;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

/* ===== Hero ===== */
.hero {
  padding: 96px 0 80px;
  text-align: center;
  background: linear-gradient(180deg, var(--color-accent-light) 0%, #ffffff 100%);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 999px;
  background: var(--color-accent-light);
  color: var(--color-accent-dark);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  max-width: 760px;
  margin: 0 auto 20px;
}

.hero h1 .accent { color: var(--color-accent); }

.hero p.subhead {
  max-width: 560px;
  margin: 0 auto 36px;
  color: var(--color-muted);
  font-size: 1.1rem;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.15s ease, background 0.15s ease, box-shadow 0.15s ease;
}

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

.btn-primary {
  background: var(--color-accent);
  color: #fff;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover { background: var(--color-accent-dark); }

.btn-secondary {
  background: #fff;
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn-secondary:hover { border-color: var(--color-accent); }

.hero-meta {
  margin-top: 20px;
  color: var(--color-muted);
  font-size: 0.85rem;
}

/* ===== Section shared ===== */
section { padding: 88px 0; }

.section-header {
  text-align: center;
  max-width: 620px;
  margin: 0 auto 56px;
}

.eyebrow {
  color: var(--color-accent);
  font-weight: 700;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 12px;
}

.section-header h2 {
  font-size: clamp(1.7rem, 3.5vw, 2.3rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
}

.section-header p {
  color: var(--color-muted);
  font-size: 1.05rem;
}

/* ===== Topics grid ===== */
.topics-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.topic-card {
  padding: 32px 28px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: #fff;
  transition: box-shadow 0.2s ease, transform 0.2s ease, border-color 0.2s ease;
}

.topic-card:hover {
  box-shadow: var(--shadow-md);
  border-color: transparent;
  transform: translateY(-3px);
}

.topic-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: var(--color-accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 18px;
}

.topic-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.topic-card p {
  color: var(--color-muted);
  font-size: 0.95rem;
}

/* ===== How it works ===== */
.how {
  background: var(--color-bg-alt);
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  position: relative;
}

.step {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  position: relative;
}

.step-number {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 18px;
}

.step h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.step p {
  color: var(--color-muted);
  font-size: 0.95rem;
}

/* ===== Final CTA ===== */
.cta-band {
  text-align: center;
  padding: 80px 0;
}

.cta-box {
  max-width: 720px;
  margin: 0 auto;
  padding: 56px 40px;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-dark) 100%);
  color: #fff;
}

.cta-box h2 {
  font-size: clamp(1.6rem, 3.5vw, 2.1rem);
  font-weight: 800;
  margin-bottom: 14px;
  letter-spacing: -0.02em;
}

.cta-box p {
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 30px;
  font-size: 1.05rem;
}

.cta-box .btn-primary {
  background: #fff;
  color: var(--color-accent-dark);
  box-shadow: none;
}

.cta-box .btn-primary:hover { background: #f3edfe; }

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 40px 0;
}

.site-footer .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

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

.footer-links a {
  color: var(--color-muted);
  font-size: 0.9rem;
  transition: color 0.15s ease;
}

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

.footer-copy {
  color: var(--color-muted);
  font-size: 0.9rem;
}

/* ===== Responsive ===== */
@media (max-width: 860px) {
  .topics-grid, .steps { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 720px) {
  .nav-links {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: #fff;
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    align-items: flex-start;
    padding: 20px 24px;
    gap: 18px;
    display: none;
  }

  .nav-links.open { display: flex; }

  .nav-toggle { display: block; }

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

  .hero { padding: 64px 0 56px; }

  section { padding: 64px 0; }
}