:root {
  --bg-primary: #f8fafc;
  --bg-secondary: #f1f5f9;
  --bg-card: #ffffff;
  --bg-card-hover: #f8fafc;
  --border: #e2e8f0;
  --border-active: #4d7cff;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --accent: #4d7cff;
  --accent-glow: rgba(77, 124, 255, 0.1);
  --accent-green: #10b981;
  --radius: 14px;
  --radius-sm: 8px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.06);
}

body.dark-mode {
  --bg-primary: #0a0e17;
  --bg-secondary: #111827;
  --bg-card: #1a2236;
  --bg-card-hover: #1f2a42;
  --border: #2a3650;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-glow: rgba(77, 124, 255, 0.15);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
}

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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.6;
}

header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 14, 23, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 1.35rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent), #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

#dark-mode-toggle {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
}

#dark-mode-toggle:hover {
  background: var(--bg-card-hover);
  color: var(--accent);
  border-color: var(--accent);
}

.hero {
  text-align: center;
  padding: 80px 24px 60px;
  max-width: 720px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-block;
  padding: 4px 16px;
  border-radius: 100px;
  background: var(--accent-glow);
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  margin-bottom: 20px;
  border: 1px solid rgba(77, 124, 255, 0.2);
}

.hero-title {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--text-primary), var(--text-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.portfolio {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

.portfolio-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 20px;
}

.site-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
  cursor: pointer;
}

.site-card:hover {
  border-color: rgba(77, 124, 255, 0.3);
  box-shadow: var(--shadow-card);
}

.site-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 22px;
  gap: 12px;
  user-select: none;
}

.site-name {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.site-name .icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background: var(--accent-glow);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 700;
  flex-shrink: 0;
}

.chevron {
  color: var(--text-muted);
  transition: transform var(--transition), color var(--transition);
  flex-shrink: 0;
}

.site-card.open .chevron {
  transform: rotate(180deg);
  color: var(--accent);
}

.site-versions {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.3s ease;
  opacity: 0;
}

.site-card.open .site-versions {
  max-height: 500px;
  opacity: 1;
}

.versions-inner {
  padding: 0 22px 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.version-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 100px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.82rem;
  font-weight: 500;
  text-decoration: none;
  transition: var(--transition);
}

.version-link:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px var(--accent-glow);
}

.version-link .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-green);
}

footer {
  margin-top: auto;
  border-top: 1px solid var(--border);
  background: var(--bg-secondary);
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  text-align: center;
}

.footer-inner p {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
}

.footer-links a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  transition: var(--transition);
}

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

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 640px) {
  .portfolio-grid {
    grid-template-columns: 1fr;
  }
  .hero {
    padding: 48px 20px 40px;
  }
  .header-inner {
    padding: 12px 16px;
  }
  .versions-inner {
    padding: 0 16px 14px;
  }
  .site-card-header {
    padding: 14px 16px;
  }
}