/* Theme: Northern Aurora - Ethereal Light Waves */
[data-theme="northern-aurora"] {
  /* Color Palette */
  --bg: #0a1218;
  --bg-alt: #121c26;
  --accent: #64ffda;
  --accent-alt: #82b1ff;
  --text: #e4f9f5;
  --muted: #94c9c0;
  --border: rgba(100, 255, 218, 0.14);
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, rgba(100, 255, 218, 0.18), rgba(130, 177, 255, 0.12));
  --gradient-radial: radial-gradient(ellipse at 50% 0%, rgba(100, 255, 218, 0.08), rgba(130, 177, 255, 0.06) 50%, transparent 70%);
  --gradient-card: linear-gradient(145deg, rgba(10, 18, 24, 0.92), rgba(18, 28, 38, 0.88));
  
  /* Effects */
  --glow-intensity: 0.88;
  --particle-color: rgba(100, 255, 218, 0.7);
  --blur-amount: 19px;
  
  /* Animation */
  --animation-speed: 0.9;
  --transition-timing: cubic-bezier(0.4, 0.0, 0.2, 1);
}

[data-theme="northern-aurora"] body {
  background: var(--gradient-radial), var(--bg);
  animation: aurora-shift 20s ease-in-out infinite;
}

@keyframes aurora-shift {
  0%, 100% {
    background: radial-gradient(ellipse at 50% 0%, rgba(100, 255, 218, 0.08), rgba(130, 177, 255, 0.06) 50%, transparent 70%), #0a1218;
  }
  50% {
    background: radial-gradient(ellipse at 50% 0%, rgba(130, 177, 255, 0.08), rgba(100, 255, 218, 0.06) 50%, transparent 70%), #0a1218;
  }
}

[data-theme="northern-aurora"] .site-header {
  background: var(--gradient-primary);
  border-bottom-color: rgba(100, 255, 218, 0.25);
  box-shadow: 0 4px 20px rgba(100, 255, 218, 0.12);
}

[data-theme="northern-aurora"] .hero-art {
  border-color: rgba(100, 255, 218, 0.22);
  background: 
    radial-gradient(ellipse at 40% 20%, rgba(100, 255, 218, 0.12), transparent 60%),
    radial-gradient(ellipse at 70% 70%, rgba(130, 177, 255, 0.1), transparent 60%),
    rgba(10, 18, 24, 0.75);
  box-shadow: 
    0 0 40px rgba(100, 255, 218, 0.15),
    0 34px 78px rgba(0, 0, 0, 0.55);
}

[data-theme="northern-aurora"] .hero-copy {
  background: var(--gradient-card);
  backdrop-filter: blur(var(--blur-amount));
  border-color: rgba(100, 255, 218, 0.18);
}

[data-theme="northern-aurora"] .cta {
  background: linear-gradient(120deg, var(--accent), var(--accent-alt));
  box-shadow: 0 18px 36px rgba(100, 255, 218, 0.3);
}

[data-theme="northern-aurora"] .cta:hover:not(:disabled) {
  box-shadow: 0 24px 48px rgba(130, 177, 255, 0.35);
  transform: translateY(-2px);
}

[data-theme="northern-aurora"] .price-chip {
  background: rgba(100, 255, 218, 0.15);
  border: 1px solid rgba(100, 255, 218, 0.25);
  box-shadow: 0 0 15px rgba(100, 255, 218, 0.15);
}

[data-theme="northern-aurora"] .price-chip.ghost {
  background: rgba(130, 177, 255, 0.15);
  border-color: rgba(130, 177, 255, 0.25);
  box-shadow: 0 0 15px rgba(130, 177, 255, 0.15);
}

/* Aurora Wave Effect */
[data-theme="northern-aurora"] .particle-aurora {
  position: fixed;
  top: -10%;
  left: 0;
  width: 100%;
  height: 40%;
  pointer-events: none;
  z-index: 1;
  overflow: hidden;
  opacity: 0.5;
}

[data-theme="northern-aurora"] .aurora-wave {
  position: absolute;
  width: 200%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(100, 255, 218, 0.15) 20%,
    rgba(130, 177, 255, 0.12) 40%,
    rgba(100, 255, 218, 0.15) 60%,
    transparent
  );
  animation: aurora-flow 30s ease-in-out infinite;
  transform-origin: center;
}

@keyframes aurora-flow {
  0% {
    transform: translateX(-50%) translateY(0) rotate(0deg);
    opacity: 0.3;
  }
  50% {
    transform: translateX(0%) translateY(-5%) rotate(2deg);
    opacity: 0.5;
  }
  100% {
    transform: translateX(-50%) translateY(0) rotate(0deg);
    opacity: 0.3;
  }
}

/* Light Particle Effect */
[data-theme="northern-aurora"] .light-particle {
  position: absolute;
  width: 3px;
  height: 3px;
  background: var(--particle-color);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--particle-color);
  animation: float-ethereal linear infinite;
  opacity: 0.6;
}

@keyframes float-ethereal {
  0% {
    transform: translateY(0) translateX(0) scale(1);
    opacity: 0;
  }
  10% {
    opacity: 0.6;
  }
  90% {
    opacity: 0.6;
  }
  100% {
    transform: translateY(-80vh) translateX(30px) scale(0.8);
    opacity: 0;
  }
}

[data-theme="northern-aurora"] .brand-mark {
  filter: drop-shadow(0 0 18px rgba(100, 255, 218, 0.4));
  animation: shimmer 3s ease-in-out infinite;
}

@keyframes shimmer {
  0%, 100% {
    filter: drop-shadow(0 0 18px rgba(100, 255, 218, 0.4));
  }
  50% {
    filter: drop-shadow(0 0 25px rgba(100, 255, 218, 0.6)) drop-shadow(0 0 35px rgba(130, 177, 255, 0.4));
  }
}

[data-theme="northern-aurora"] .flash-success {
  background: rgba(100, 255, 218, 0.12);
  border-color: var(--accent);
  box-shadow: 0 4px 18px rgba(100, 255, 218, 0.15);
}

[data-theme="northern-aurora"] .flash-error {
  background: rgba(130, 177, 255, 0.12);
  border-color: var(--accent-alt);
  box-shadow: 0 4px 18px rgba(130, 177, 255, 0.15);
}

/* Soft glow for interactive elements */
[data-theme="northern-aurora"] .plan-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 18px 36px rgba(100, 255, 218, 0.2);
  border-color: var(--accent);
}

[data-theme="northern-aurora"] .nav-link:hover {
  color: var(--accent);
  text-shadow: 0 0 12px rgba(100, 255, 218, 0.5);
}

[data-theme="northern-aurora"] .admin-card,
[data-theme="northern-aurora"] .experience-left,
[data-theme="northern-aurora"] .experience-right {
  backdrop-filter: blur(20px);
  border-color: rgba(100, 255, 218, 0.15);
  background: linear-gradient(145deg, rgba(10, 18, 24, 0.9), rgba(18, 28, 38, 0.85));
}

/* Ethereal transition effect */
[data-theme="northern-aurora"] * {
  transition-timing-function: var(--transition-timing);
}