:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --muted: #666;
  --primary: #4f46e5;
  --border: #e5e7eb;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

/* Layout */

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1rem;
}

.container.narrow {
  max-width: 700px;
}

.section {
  padding: 5rem 0;
}

.section.alt {
  background: #f9fafb;
}

/* Header */

.header {
  position: sticky;
  top: 0;
  background: white;
  border-bottom: 1px solid var(--border);
  z-index: 100;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-weight: 700;
  font-size: 1.1rem;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
}

.nav-links a {
  text-decoration: none;
  color: var(--text);
  font-weight: 500;
}

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

.menu-toggle {
  display: none;
  font-size: 1.5rem;
  background: none;
  border: none;
  cursor: pointer;
}

/* Hero */

.hero {
  min-height: 70vh;
  display: flex;
  align-items: center;
}

.hero h1 {
  font-size: clamp(2rem, 4vw, 3rem);
}

.hero p {
  max-width: 600px;
  color: var(--muted);
}

.btn {
  display: inline-block;
  margin-top: 1.5rem;
  padding: 0.75rem 1.25rem;
  background: var(--primary);
  color: white;
  text-decoration: none;
  border-radius: 6px;
  font-weight: 500;
}

/* Cards */

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

.card {
  padding: 1.5rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: white;
  color: inherit;
  text-decoration: none;
}

.card h3 {
  margin-top: 0;
}

/* Footer */

.footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  text-align: center;
  color: var(--muted);
}

/* Mobile */

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

  .nav-links {
    position: absolute;
    top: 64px;
    right: 0;
    background: white;
    flex-direction: column;
    width: 200px;
    border-left: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    padding: 1rem;
    display: none;
  }

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