:root {
  --bg-primary:    #05050f;
  --bg-card:       #0d0d1f;
  --bg-card-hover: #111128;
  --blue-main:     #4361ee;
  --blue-glow:     #3a86ff;
  --blue-neon:     #00b4d8;
  --blue-dim:      rgba(67, 97, 238, 0.15);
  --text-primary:  #ffffff;
  --text-secondary:#94a3b8;
  --text-muted:    #475569;
  --green:         #22c55e;
  --green-dim:     rgba(34, 197, 94, 0.15);
  --red:           #ef4444;
  --red-dim:       rgba(239, 68, 68, 0.15);
  --border:        rgba(67, 97, 238, 0.25);
  --border-hover:  rgba(58, 134, 255, 0.5);
  --radius:        14px;
  --radius-sm:     8px;
  --transition:    0.2s ease;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Space Grotesk', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(67,97,238,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(67,97,238,0.04) 1px, transparent 1px);
  background-size: 50px 50px;
  pointer-events: none;
  z-index: 0;
  animation: gridPulse 8s ease-in-out infinite alternate;
}
@keyframes gridPulse {
  from { opacity: 0.5; }
  to   { opacity: 1; }
}

.page-wrapper { position: relative; z-index: 1; }

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  backdrop-filter: blur(12px);
  transition: var(--transition);
}
.card:hover { border-color: var(--border-hover); }

.btn-primary {
  background: var(--blue-main);
  color: white;
  border: none;
  border-radius: var(--radius-sm);
  padding: 12px 28px;
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 0 20px rgba(67,97,238,0.4);
}
.btn-primary:hover {
  background: var(--blue-glow);
  box-shadow: 0 0 30px rgba(58,134,255,0.6);
  transform: translateY(-1px);
}
.btn-primary:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--blue-main); border-radius: 3px; }

.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  border-bottom: 1px solid var(--border);
}
.nav-brand {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--blue-glow);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}
.nav-brand .hex {
  width: 24px; height: 24px;
  background: var(--blue-main);
  clip-path: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
  display: inline-block;
}
.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
}
.nav-link:hover {
  color: var(--text-primary);
  background: var(--blue-dim);
}

.badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.badge-cpp { background: rgba(67,97,238,0.2); color: var(--blue-glow); }
.badge-eh  { background: rgba(168,85,247,0.2); color: #c084fc; }
.badge-ssad { background: rgba(0,180,216,0.2); color: var(--blue-neon); }

.subject-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
}

.fade-in {
  animation: fadeIn 0.4s ease forwards;
}
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

@media (max-width: 768px) {
  .nav { padding: 12px 16px; }
  .nav-brand { font-size: 1.1rem; }
}