/* ==========================================================================
   Design System - Referral Page
   ========================================================================== */

/* CSS Custom Properties */
:root {
  /* Colors - Dark Theme */
  --bg-primary: #0D0D0D;
  --bg-card: #1A1A2E;
  --bg-card-hover: #242442;

  /* Accent Colors */
  --accent-cyan: #00F5D4;
  --accent-coral: #FF6B6B;
  --accent-violet: #7B2CBF;
  --accent-gold: #FFD93D;
  --accent-blue: #4361EE;

  /* Text Colors */
  --text-primary: #FFFFFF;
  --text-secondary: #A0A0B0;
  --text-muted: #6B6B7B;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;

  /* Shadows */
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.3);
  --shadow-card-hover: 0 12px 40px rgba(0, 0, 0, 0.5);
}

/* ==========================================================================
   Base Reset
   ========================================================================== */

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

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

/* ==========================================================================
   Layout
   ========================================================================== */

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-xl) var(--space-lg);
}

.page-header {
  text-align: center;
  margin-bottom: var(--space-3xl);
}

.page-title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-sm);
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.page-subtitle {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  font-weight: 400;
}

/* ==========================================================================
   Cards Grid
   ========================================================================== */

.cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
}

@media (max-width: 1024px) {
  .cards-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .cards-grid {
    grid-template-columns: 1fr;
  }

  .container {
    padding: var(--space-lg) var(--space-md);
  }
}

/* ==========================================================================
   Card Component
   ========================================================================== */

.card {
  position: relative;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition:
    transform var(--transition-base),
    box-shadow var(--transition-base);

  /* Geometric corner cut */
  clip-path: polygon(
    0 0,
    100% 0,
    100% calc(100% - 20px),
    calc(100% - 20px) 100%,
    0 100%
  );

  /* Animation setup */
  opacity: 0;
  transform: translateY(30px);
}

.card.animate-in {
  animation: slideUp 0.5s ease forwards;
}

/* Staggered animation delays */
.card:nth-child(1) { animation-delay: 0ms; }
.card:nth-child(2) { animation-delay: 100ms; }
.card:nth-child(3) { animation-delay: 200ms; }
.card:nth-child(4) { animation-delay: 300ms; }
.card:nth-child(5) { animation-delay: 400ms; }
.card:nth-child(6) { animation-delay: 500ms; }

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

/* Accent stripe */
.card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--card-accent, var(--accent-cyan));
  animation: stripePulse 2s ease-in-out infinite;
}

@keyframes stripePulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

/* Hover states */
.card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow:
    var(--shadow-card-hover),
    0 0 30px color-mix(in srgb, var(--card-accent, var(--accent-cyan)) 30%, transparent);
}

.card:hover::before {
  animation: none;
  opacity: 1;
}

/* Card link wrapper */
.card-link {
  display: block;
  padding: var(--space-xl);
  height: 100%;
}

/* Card header */
.card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: var(--space-md);
}

.card-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.card-tagline {
  font-size: var(--font-size-sm);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Bonus badge */
.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-xs) var(--space-sm);
  background: color-mix(in srgb, var(--card-accent, var(--accent-cyan)) 20%, transparent);
  border: 1px solid var(--card-accent, var(--accent-cyan));
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--card-accent, var(--accent-cyan));
  white-space: nowrap;
}

/* Card body */
.card-description {
  color: var(--text-secondary);
  font-size: var(--font-size-base);
  line-height: 1.7;
  margin-bottom: var(--space-lg);
}

/* Features list */
.card-features {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}

.feature-tag {
  display: inline-block;
  padding: var(--space-xs) var(--space-sm);
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

/* Referral code */
.card-code {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: rgba(0, 0, 0, 0.3);
  border-radius: var(--radius-md);
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: var(--font-size-sm);
}

.card-code-label {
  color: var(--text-muted);
}

.card-code-value {
  color: var(--card-accent, var(--accent-cyan));
  font-weight: 500;
}

.copy-btn {
  margin-left: auto;
  padding: var(--space-xs) var(--space-sm);
  background: transparent;
  border: 1px solid var(--text-muted);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.copy-btn:hover {
  border-color: var(--card-accent, var(--accent-cyan));
  color: var(--card-accent, var(--accent-cyan));
}

.copy-btn.copied {
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

/* Card footer / CTA */
.card-cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  color: var(--card-accent, var(--accent-cyan));
  font-weight: 500;
  font-size: var(--font-size-sm);
  transition: gap var(--transition-fast);
}

.card:hover .card-cta {
  gap: var(--space-md);
}

.card-cta-arrow {
  transition: transform var(--transition-fast);
}

.card:hover .card-cta-arrow {
  transform: translateX(4px);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.page-footer {
  text-align: center;
  margin-top: var(--space-3xl);
  padding-top: var(--space-xl);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-muted);
  font-size: var(--font-size-sm);
}

/* ==========================================================================
   Reduced Motion
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
  .card {
    animation: none;
    opacity: 1;
    transform: none;
  }

  .card::before {
    animation: none;
  }

  .card:hover {
    transform: none;
  }
}

/* ==========================================================================
   Tilt Effect (JS-enhanced)
   ========================================================================== */

.card.tilt-enabled {
  transform-style: preserve-3d;
  perspective: 1000px;
}