:root {
  --ink: #111111;
  --paper: #ffffff;
  --muted: #6b6b6b;
  --line: #e6e6e6;
  --accent: #1a56ff;
  --radius: 2px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.5;
}

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

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

/* Header */

.site-header {
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  background: var(--paper);
  z-index: 10;
}

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

.logo {
  font-weight: 700;
  letter-spacing: 0.08em;
  font-size: 1.05rem;
}

.nav {
  display: flex;
  gap: 32px;
  font-size: 0.9rem;
}

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

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

/* Hero */

.hero {
  padding: 120px 0 96px;
  border-bottom: 1px solid var(--line);
}

.hero-inner {
  max-width: 640px;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 0 0 24px;
}

.hero-sub {
  color: var(--muted);
  font-size: 1.05rem;
  margin: 0 0 32px;
  max-width: 46ch;
}

.btn-primary {
  display: inline-block;
  background: var(--accent);
  color: var(--paper);
  padding: 14px 28px;
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 600;
}

.btn-primary:hover {
  opacity: 0.9;
}

.btn-outline {
  display: inline-block;
  border: 1px solid var(--ink);
  padding: 13px 27px;
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 600;
  white-space: nowrap;
}

.btn-outline:hover {
  background: var(--ink);
  color: var(--paper);
}

/* Grid section */

.grid-section {
  padding: 96px 0;
  border-bottom: 1px solid var(--line);
}

.grid-section h2 {
  font-size: 1.6rem;
  margin: 0 0 48px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}

.card {
  border-top: 2px solid var(--ink);
  padding-top: 20px;
}

.card-tag {
  color: var(--muted);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
}

.card h3 {
  margin: 8px 0 12px;
  font-size: 1.15rem;
}

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

/* CTA band */

.cta-band {
  padding: 80px 0;
}

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

.cta-inner h2 {
  font-size: 1.4rem;
  margin: 0 0 8px;
}

.cta-inner p {
  color: var(--muted);
  margin: 0;
  max-width: 44ch;
}

/* Footer */

.site-footer {
  border-top: 1px solid var(--line);
  padding: 28px 0;
}

.footer-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
}

.muted {
  color: var(--muted);
}

@media (max-width: 720px) {
  .nav {
    position: fixed;
    inset: 72px 0 0 0;
    background: var(--paper);
    flex-direction: column;
    padding: 24px;
    gap: 20px;
    font-size: 1.1rem;
    transform: translateY(-100%);
    transition: transform 0.2s ease;
  }

  .nav.open {
    transform: translateY(0);
  }

  .nav-toggle {
    display: block;
    width: 28px;
    height: 20px;
    position: relative;
  }

  .nav-toggle span,
  .nav-toggle::before,
  .nav-toggle::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--ink);
  }

  .nav-toggle::before {
    top: 0;
  }

  .nav-toggle span {
    top: 9px;
  }

  .nav-toggle::after {
    bottom: 0;
  }

  .card-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .cta-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}