:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f5f6f8;
  --color-text: #1a1a1a;
  --color-muted: #5b5f66;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --max-width: 960px;
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header */

.site-header {
  border-bottom: 1px solid #e5e7eb;
  position: sticky;
  top: 0;
  background: var(--color-bg);
  z-index: 10;
}

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

.logo {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-text);
  text-decoration: none;
}

.site-header nav ul {
  list-style: none;
  display: flex;
  gap: 1.5rem;
  margin: 0;
  padding: 0;
}

.site-header nav a {
  color: var(--color-muted);
  text-decoration: none;
  font-size: 0.95rem;
}

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

/* Hero */

.hero {
  padding: 5rem 0;
  text-align: center;
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

.hero p {
  color: var(--color-muted);
  font-size: 1.1rem;
  margin-bottom: 2rem;
}

.button {
  display: inline-block;
  background: var(--color-accent);
  color: #fff;
  text-decoration: none;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  transition: background 0.15s ease;
}

.button:hover {
  background: var(--color-accent-hover);
}

/* Sections */

.section {
  padding: 4rem 0;
}

.section-alt {
  background: var(--color-bg-alt);
}

.section h2 {
  font-size: 1.8rem;
  margin-bottom: 1rem;
}

/* Cards */

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.card {
  background: var(--color-bg);
  border: 1px solid #e5e7eb;
  border-radius: var(--radius);
  padding: 1.5rem;
}

.card h3 {
  margin-top: 0;
}

/* Footer */

.site-footer {
  border-top: 1px solid #e5e7eb;
  padding: 1.5rem 0;
  text-align: center;
  color: var(--color-muted);
  font-size: 0.9rem;
}

/* Responsive */

@media (max-width: 600px) {
  .site-header .container {
    flex-direction: column;
    height: auto;
    padding: 1rem 1.5rem;
    gap: 0.5rem;
  }

  .hero h1 {
    font-size: 2rem;
  }
}