/* ==========================================================================
   ⚡ VERIFICATION LEARNING PLATFORM - HOME PAGE DESIGN SYSTEM
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600;700&family=Outfit:wght@400;500;600;700;800;900&display=swap');

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

:root {
  --bg-base: #0a0e17;
  --bg-surface: #111827;
  --bg-card: rgba(17, 24, 39, 0.7);
  --border-subtle: rgba(55, 65, 81, 0.5);
  --border-glow: rgba(99, 102, 241, 0.3);
  --text-primary: #f0f4fc;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  --accent-uvm: #6366f1;
  --accent-sv: #10b981;
  --accent-practical: #f59e0b;
  --accent-orange: #ea580c;
  --accent-cyan: #22d3ee;
  --accent-pink: #f472b6;
  --accent-amber: #fbbf24;
  --font-heading: 'Outfit', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
}

body {
  background: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-heading);
  min-height: 100vh;
  overflow-x: hidden;
}

/* Animated Background */
.bg-grid {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background-image:
    linear-gradient(rgba(99, 102, 241, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(99, 102, 241, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  z-index: 0;
  pointer-events: none;
}

.bg-glow-orb {
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.15;
  pointer-events: none;
  z-index: 0;
  animation: floatOrb 20s ease-in-out infinite;
}
.bg-glow-orb.orb-1 { width: 500px; height: 500px; background: var(--accent-uvm); top: -10%; left: -5%; }
.bg-glow-orb.orb-2 { width: 400px; height: 400px; background: var(--accent-sv); bottom: -5%; right: -5%; animation-delay: -7s; }
.bg-glow-orb.orb-3 { width: 300px; height: 300px; background: var(--accent-cyan); top: 40%; left: 50%; animation-delay: -14s; }

@keyframes floatOrb {
  0%, 100% { transform: translate(0, 0) scale(1); }
  25% { transform: translate(30px, -20px) scale(1.05); }
  50% { transform: translate(-20px, 30px) scale(0.95); }
  75% { transform: translate(20px, 20px) scale(1.02); }
}

/* Navigation */
.nav-bar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 0.75rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(10, 14, 23, 0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-subtle);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 800;
  font-size: 1.1rem;
  letter-spacing: -0.02em;
}

.nav-brand .icon { font-size: 1.3rem; }

.nav-links {
  display: flex;
  gap: 0.5rem;
}

.nav-link {
  padding: 0.4rem 1rem;
  border-radius: 8px;
  text-decoration: none;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: all 0.2s;
  border: 1px solid transparent;
}
.nav-link:hover {
  color: var(--text-primary);
  background: rgba(255,255,255,0.05);
  border-color: var(--border-subtle);
}
.nav-link.github {
  border-color: var(--border-subtle);
  background: rgba(255,255,255,0.03);
}

/* Hero */
.hero {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 8rem 2rem 3rem;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 1rem;
  border-radius: 100px;
  border: 1px solid var(--border-subtle);
  background: rgba(255,255,255,0.03);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.hero-badge .dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent-sv);
  animation: pulse 2s ease infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.3); }
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.04em;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, #f0f4fc 0%, #a5b4fc 40%, #22d3ee 70%, #10b981 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 2rem;
  line-height: 1.6;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  margin-bottom: 1rem;
}

.hero-stat {
  text-align: center;
}
.hero-stat .num {
  font-size: 2rem;
  font-weight: 800;
  font-family: var(--font-mono);
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-sv));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-stat .label {
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 600;
}

/* Course Cards Grid */
.courses-section {
  position: relative;
  z-index: 1;
  max-width: 1280px;
  margin: 0 auto;
  padding: 2rem;
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 1.5rem;
}

.course-card {
  position: relative;
  border-radius: 16px;
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  backdrop-filter: blur(20px);
  overflow: hidden;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
  display: block;
}

.course-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  border-radius: 16px 16px 0 0;
  opacity: 0;
  transition: opacity 0.35s;
}
.course-card.uvm::before { background: linear-gradient(90deg, var(--accent-uvm), var(--accent-pink)); }
.course-card.sv::before { background: linear-gradient(90deg, var(--accent-sv), var(--accent-cyan)); }
.course-card.practical-uvm::before { background: linear-gradient(90deg, var(--accent-practical), var(--accent-orange)); }

.course-card:hover {
  transform: translateY(-4px);
  border-color: rgba(255,255,255,0.1);
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
}
.course-card:hover::before { opacity: 1; }

.card-header {
  padding: 1.75rem 1.75rem 0;
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.card-icon {
  width: 56px; height: 56px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  flex-shrink: 0;
}
.course-card.uvm .card-icon { background: rgba(99, 102, 241, 0.15); border: 1px solid rgba(99, 102, 241, 0.25); }
.course-card.sv .card-icon { background: rgba(16, 185, 129, 0.15); border: 1px solid rgba(16, 185, 129, 0.25); }
.course-card.practical-uvm .card-icon { background: rgba(245, 158, 11, 0.15); border: 1px solid rgba(245, 158, 11, 0.25); }

.card-title-group h2 {
  font-size: 1.3rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
}
.card-title-group .subtitle {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.card-body {
  padding: 1rem 1.75rem;
}
.card-body p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.card-tags {
  padding: 0 1.75rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.tag {
  padding: 0.2rem 0.6rem;
  border-radius: 6px;
  font-size: 0.65rem;
  font-weight: 600;
  font-family: var(--font-mono);
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
  color: var(--text-secondary);
}

.card-footer {
  padding: 1.25rem 1.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid rgba(255,255,255,0.04);
  margin-top: 1rem;
}

.card-meta {
  display: flex;
  gap: 1.25rem;
}
.card-meta-item {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}
.card-meta-item .icon { font-size: 0.85rem; }

.card-action {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 0.5rem 1.2rem;
  border-radius: 10px;
  transition: all 0.2s;
}
.course-card.uvm .card-action { color: var(--accent-uvm); background: rgba(99, 102, 241, 0.1); }
.course-card.sv .card-action { color: var(--accent-sv); background: rgba(16, 185, 129, 0.1); }
.course-card.practical-uvm .card-action { color: var(--accent-practical); background: rgba(245, 158, 11, 0.1); }
.course-card:hover .card-action { transform: translateX(3px); }

/* Footer */
.footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 3rem 2rem;
  margin-top: 2rem;
  border-top: 1px solid var(--border-subtle);
}
.footer p {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.8;
}
.footer a {
  color: var(--accent-cyan);
  text-decoration: none;
}
.footer a:hover { text-decoration: underline; }

/* Responsive */
@media (max-width: 768px) {
  .courses-grid { grid-template-columns: 1fr; }
  .hero { padding-top: 6rem; }
  .hero-stats { gap: 1.5rem; }
  .nav-bar { padding: 0.5rem 1rem; }
}