:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --muted: #5a6573;
  --accent: #3b5998;
  --accent-hover: #2d4373;
  --border: #e5e7eb;
  --surface: #f8fafc;
  --max-width: 1080px;
  --radius: 8px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }

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

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

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

/* Header */
header {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
}
header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 18px;
  padding-bottom: 18px;
}
.brand {
  font-weight: 700;
  font-size: 20px;
  color: var(--text);
  text-decoration: none;
}
.brand:hover { text-decoration: none; color: var(--text); }
nav a {
  margin-left: 24px;
  color: var(--muted);
  font-size: 15px;
}
nav a.cta {
  background: var(--accent);
  color: #fff;
  padding: 8px 16px;
  border-radius: var(--radius);
  font-weight: 600;
}
nav a.cta:hover { background: var(--accent-hover); color: #fff; text-decoration: none; }

/* Hero */
.hero {
  padding: 88px 0 72px;
  text-align: center;
}
.hero h1 {
  font-size: 48px;
  line-height: 1.15;
  margin: 0 0 20px;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.hero p.lede {
  font-size: 20px;
  color: var(--muted);
  max-width: 640px;
  margin: 0 auto 36px;
}
.hero .actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}
.btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 16px;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: var(--accent-hover); color: #fff; text-decoration: none; }
.btn-secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: var(--surface); text-decoration: none; }

/* Features */
.features {
  padding: 72px 0;
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.features h2 {
  text-align: center;
  font-size: 32px;
  margin: 0 0 48px;
  letter-spacing: -0.01em;
}
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}
.feature {
  background: var(--bg);
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.feature h3 {
  margin: 0 0 12px;
  font-size: 18px;
  font-weight: 600;
}
.feature p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
}

/* Page (about/contact) */
.page {
  padding: 72px 0;
  max-width: 720px;
  margin: 0 auto;
}
.page h1 {
  font-size: 36px;
  margin: 0 0 24px;
  letter-spacing: -0.01em;
}
.page p {
  font-size: 17px;
  color: var(--text);
  margin: 0 0 18px;
}
.page p.muted { color: var(--muted); }

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
  margin-top: 64px;
  color: var(--muted);
  font-size: 14px;
}
footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

/* Responsive */
@media (max-width: 720px) {
  .hero { padding: 56px 0 48px; }
  .hero h1 { font-size: 36px; }
  .hero p.lede { font-size: 17px; }
  .feature-grid { grid-template-columns: 1fr; gap: 16px; }
  .features { padding: 48px 0; }
  nav a { margin-left: 16px; font-size: 14px; }
  nav a.cta { padding: 6px 12px; }
}