:root {
  --bg: #0f172a;
  --bg-alt: #1e293b;
  --surface: #ffffff;
  --text: #1e293b;
  --muted: #64748b;
  --accent: #6366f1;
  --accent-dark: #4f46e5;
  --border: #e2e8f0;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: #f8fafc;
  line-height: 1.6;
}

.container {
  width: min(1100px, 90%);
  margin: 0 auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  z-index: 10;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
}

.brand {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
}

.nav a {
  margin-left: 1.5rem;
  color: var(--muted);
  text-decoration: none;
  font-weight: 500;
}

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

/* Hero */
.hero {
  background: linear-gradient(135deg, var(--bg), var(--bg-alt));
  color: #fff;
  text-align: center;
  padding: 6rem 0;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  margin-bottom: 1rem;
}

.hero-sub {
  max-width: 600px;
  margin: 0 auto 2rem;
  color: #cbd5e1;
  font-size: 1.1rem;
}

.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 0.85rem 2rem;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 600;
  transition: background 0.2s ease;
}

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

/* Sections */
.section {
  padding: 4rem 0;
}

.section-alt {
  background: #fff;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section h2 {
  font-size: 2rem;
  margin-bottom: 1.5rem;
  text-align: center;
}

.section p {
  max-width: 700px;
  margin: 0 auto;
  color: var(--muted);
  text-align: center;
}

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

/* Cards */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.75rem;
  text-align: center;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.08);
}

.card-emoji {
  font-size: 2.5rem;
  margin-bottom: 0.75rem;
}

.card h3 {
  margin-bottom: 0.5rem;
}

.card p {
  color: var(--muted);
  margin-bottom: 1rem;
}

.card-link {
  color: var(--accent);
  font-weight: 600;
  text-decoration: none;
}

.card-link:hover {
  text-decoration: underline;
}

/* Footer */
.site-footer {
  background: var(--bg);
  color: #94a3b8;
  text-align: center;
  padding: 2rem 0;
}