:root {
  --bg-dark: #0d1117;
  --bg-light: #f0f4f8;
  --text-light: #f4f4f4;
  --accent: #00c2ff;
  --font: 'Space Grotesk', sans-serif;
}

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

body {
  font-family: var(--font);
  background: var(--bg-light);
  color: #111;
  scroll-behavior: smooth;
}

header {
  background: var(--bg-dark);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav {
  max-width: 1100px;
  margin: auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-light);
}

.logo {
  font-size: 1.4rem;
  font-weight: 600;
}

nav a {
  margin-left: 1.5rem;
  color: var(--text-light);
  text-decoration: none;
  font-size: 1rem;
  transition: color 0.2s ease;
}

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

.hero {
  height: 90vh;
  background: linear-gradient(120deg, #001f3f, #003366);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 0 1rem;
}

.hero-content h1 {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.hero-content p {
  font-size: 1.2rem;
  margin-bottom: 2rem;
}

.cta-btn {
  background: var(--accent);
  color: #000;
  padding: 0.8rem 1.5rem;
  text-decoration: none;
  font-weight: bold;
  border-radius: 30px;
  transition: background 0.3s ease;
}

.cta-btn:hover {
  background: #00a0d1;
}

.cta-btn.alt {
  background: white;
  color: #003366;
}

.section {
  padding: 4rem 1rem;
}

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

.section p {
  text-align: center;
  max-width: 800px;
  margin: auto;
  font-size: 1.1rem;
}

.dark {
  background: var(--bg-dark);
  color: var(--text-light);
}

.light {
  background: var(--bg-light);
  color: #000;
}

.grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  margin-top: 2rem;
}

.card {
  background: white;
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.05);
  transition: transform 0.3s;
}

.card:hover {
  transform: translateY(-5px);
}

.dark .card {
  background: #161b22;
  color: var(--text-light);
}

.join {
  text-align: center;
}

footer {
  background: var(--bg-dark);
  color: var(--text-light);
  padding: 2rem 1rem;
}

.footer {
  max-width: 1100px;
  margin: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.footer a {
  color: var(--accent);
  text-decoration: none;
  margin: 0 0.5rem;
}

@media (min-width: 768px) {
  .footer {
    flex-direction: row;
    justify-content: space-between;
  }
}