:root {
  --primary-color: #84cc16; /* 연두색 */
  --secondary-color: #65a30d;
  --bg-color: #ffffff;
  --text-color: #1e293b;
  --card-bg: #f9fafb;
  --nav-bg: rgba(255, 255, 255, 0.9);
  --border-color: #e2e8f0;
}

[data-theme='dark'] {
  --bg-color: #0f172a;
  --text-color: #f8fafc;
  --card-bg: #1e293b;
  --nav-bg: rgba(15, 23, 42, 0.9);
  --border-color: #334155;
}

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

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;
  line-height: 1.7;
  transition: background-color 0.3s, color 0.3s;
}

nav {
  position: fixed;
  top: 0; width: 100%;
  display: flex; justify-content: space-between; align-items: center;
  padding: 1rem 10%;
  background: var(--nav-bg);
  backdrop-filter: blur(10px);
  z-index: 1000;
  border-bottom: 1px solid var(--border-color);
}

.logo { font-size: 1.4rem; font-weight: 800; color: var(--primary-color); letter-spacing: -0.5px; }

.nav-links a {
  margin: 0 1rem;
  text-decoration: none;
  color: var(--text-color);
  font-weight: 600;
  font-size: 0.95rem;
  transition: color 0.2s;
}

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

#theme-toggle {
  background: none;
  border: 1px solid var(--border-color);
  padding: 0.4rem 0.8rem;
  border-radius: 20px;
  cursor: pointer;
  color: var(--text-color);
  font-size: 0.85rem;
}

.hero {
  padding: 10rem 10% 6rem;
  text-align: center;
  background: linear-gradient(135deg, rgba(132,204,22,0.1) 0%, rgba(34,197,94,0.05) 100%);
}

.hero h1 { font-size: 3.2rem; margin-bottom: 1.5rem; line-height: 1.2; font-weight: 800; }

.section-title {
  text-align: center;
  font-size: 2.2rem;
  margin-bottom: 3.5rem;
  font-weight: 700;
}

.content-section, .articles-section {
  padding: 6rem 10%;
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2.5rem;
}

.card {
  background: var(--card-bg);
  padding: 2.5rem;
  border-radius: 16px;
  border: 1px solid var(--border-color);
  transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  text-align: center;
}

.card:hover { transform: translateY(-8px); box-shadow: 0 20px 25px -5px rgba(0,0,0,0.1); }

.card i { color: var(--primary-color); margin-bottom: 1.5rem; width: 48px; height: 48px; }

/* Article Grid */
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
  gap: 2.5rem;
}

.article-card {
  background: var(--card-bg);
  border-radius: 20px;
  overflow: hidden;
  border: 1px solid var(--border-color);
  transition: 0.3s;
}

.article-card:hover { transform: scale(1.02); }

.article-card img {
  width: 100%;
  height: 220px;
  object-fit: cover;
}

.article-body { padding: 2rem; }

.category {
  font-size: 0.75rem;
  color: var(--primary-color);
  font-weight: 800;
  margin-bottom: 0.5rem;
  display: block;
}

.read-more {
  display: inline-block;
  margin-top: 1.2rem;
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 700;
}

footer {
  background: var(--bg-color);
  padding: 5rem 10%;
  border-top: 1px solid var(--border-color);
  text-align: center;
}

.footer-links { margin: 2rem 0; }
.footer-links a { margin: 0 1.2rem; text-decoration: none; color: #64748b; font-size: 0.95rem; }

.primary-btn {
  background: var(--primary-color);
  color: white;
  padding: 1.2rem 3rem;
  border: none;
  border-radius: 12px;
  font-weight: 700;
  font-size: 1.1rem;
  cursor: pointer;
  box-shadow: 0 10px 15px -3px rgba(132,204,22,0.3);
  transition: 0.2s;
}

.primary-btn:hover { background: var(--secondary-color); transform: translateY(-2px); }

/* Animations */
.animate-up {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeUp 0.8s forwards;
}
.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }

@keyframes fadeUp {
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 768px) {
  .hero h1 { font-size: 2.2rem; }
  .nav-links { display: none; }
}