:root {
  /* Color Palette - Premium Dark Mode with Amber Accents */
  --bg-primary: #0f172a; /* Slate 900 */
  --bg-secondary: #1e293b; /* Slate 800 */
  --bg-tertiary: #334155; /* Slate 700 */
  
  --text-primary: #f8fafc; /* Slate 50 */
  --text-secondary: #94a3b8; /* Slate 400 */
  
  --accent-primary: #f59e0b; /* Amber 500 */
  --accent-secondary: #d97706; /* Amber 600 */
  --accent-glow: rgba(245, 158, 11, 0.2);
  
  --danger-primary: #ef4444; /* Red 500 */
  
  --border-color: #334155;
  --glass-bg: rgba(30, 41, 59, 0.6);
  --glass-border: rgba(255, 255, 255, 0.08);

  /* Typography */
  --font-family: 'Inter', system-ui, -apple-system, sans-serif;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 4rem;
  
  /* Layout */
  --max-width: 1200px;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

/* Typography */
h1, h2, h3, h4 {
  line-height: 1.2;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(2rem, 4vw, 3rem);
}

h3 {
  font-size: 1.5rem;
}

p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
  font-size: 1.125rem;
}

/* Layout Utilities */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.section {
  padding: var(--spacing-xl) 0;
}

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  padding: var(--spacing-md) 0;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
  z-index: 100;
  transition: all 0.3s ease;
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.brand-icon {
  color: var(--accent-primary);
}

.nav-links {
  display: flex;
  gap: var(--spacing-lg);
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color 0.2s ease;
}

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

/* Hero Section */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 80px;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  top: 20%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
  z-index: -1;
  pointer-events: none;
}

.hero-content {
  max-width: 800px;
  text-align: center;
  margin: 0 auto;
}

.hero-subtitle {
  color: var(--accent-primary);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.875rem;
  margin-bottom: var(--spacing-md);
  display: block;
}

.hero p {
  font-size: 1.25rem;
  max-width: 600px;
  margin: 0 auto var(--spacing-lg);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 1.5rem;
  font-weight: 600;
  border-radius: 8px;
  transition: all 0.2s ease;
  cursor: pointer;
  border: none;
  gap: 0.5rem;
}

.btn-primary {
  background-color: var(--accent-primary);
  color: #fff;
  box-shadow: 0 4px 14px 0 var(--accent-glow);
}

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

.btn-secondary {
  background-color: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background-color: var(--bg-tertiary);
}

/* Grid Layouts */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
}

/* Glass Cards */
.glass-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  padding: var(--spacing-lg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.glass-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  border-color: var(--accent-primary);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: var(--bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-md);
  color: var(--accent-primary);
  font-size: 1.5rem;
}

.glass-card h3 {
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

.glass-card p {
  font-size: 1rem;
  margin-bottom: 0;
}

/* Guide Section (For specific pages) */
.guide-header {
  padding: calc(var(--spacing-xl) * 2) 0 var(--spacing-xl);
  border-bottom: 1px solid var(--border-color);
  background: linear-gradient(to bottom, var(--bg-secondary), var(--bg-primary));
}

.guide-content {
  padding: var(--spacing-xl) 0;
}

.question-block {
  margin-bottom: var(--spacing-xl);
}

.question-block h2 {
  color: var(--accent-primary);
  font-size: 1.25rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-sm);
}

.question-block h3 {
  font-size: 2rem;
  margin-bottom: var(--spacing-md);
}

.question-block p {
  font-size: 1.125rem;
}

/* Footer */
footer {
  background-color: var(--bg-secondary);
  padding: var(--spacing-xl) 0 var(--spacing-md);
  border-top: 1px solid var(--border-color);
  margin-top: var(--spacing-xl);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-lg);
}

.footer-bottom {
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.875rem;
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--border-color);
}

/* Responsive */
@media (max-width: 768px) {
  .navbar .container {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
  
  .nav-links {
    gap: var(--spacing-md);
    flex-wrap: wrap;
    justify-content: center;
  }
  
  .nav-links a {
    font-size: 0.85rem;
  }

  .hero {
    padding-top: 120px; /* Account for taller stacked navbar */
  }
  
  .hero-content {
    text-align: center;
  }
  
  .btn {
    width: 100%;
    margin-bottom: var(--spacing-sm);
  }
  
  .hero .btn-container {
    flex-direction: column;
  }
  
  .section {
    padding: var(--spacing-lg) 0;
  }
  
  .grid-2, .grid-3 {
    grid-template-columns: 1fr;
  }
}

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

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