/* Particle course accent: cyan/magenta spark theme */
  .header-badge { background: linear-gradient(90deg, #00d4ff, #ff00aa); }
  header h1 { background: linear-gradient(135deg, #fff 15%, #00d4ff 50%, #ff00aa); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
  header::before {
    background: radial-gradient(circle at 20% 60%, rgba(0,212,255,0.2) 0%, transparent 55%),
                radial-gradient(circle at 80% 25%, rgba(255,0,170,0.18) 0%, transparent 50%),
                radial-gradient(circle at 55% 80%, rgba(255,209,102,0.1) 0%, transparent 40%);
  }
  .nav-item.active { border-left-color: #00d4ff; }
  .lesson-num { color: #00d4ff; }

  /* Particle preview boxes */
  .particle-demo {
    background: #0a0a14;
    border: 1px solid var(--border);
    border-radius: 14px;
    height: 180px;
    position: relative;
    overflow: hidden;
    margin: 18px 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    letter-spacing: 8px;
  }
  .particle-demo .demo-label {
    position: absolute;
    top: 10px;
    left: 14px;
    font-size: 11px;
    font-weight: 800;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--muted);
  }

  /* Animated particles in demo boxes */
  @keyframes rain   { 0%{transform:translateY(-10px);opacity:1} 100%{transform:translateY(180px);opacity:0} }
  @keyframes snow   { 0%{transform:translateY(-10px) translateX(0);opacity:1} 100%{transform:translateY(180px) translateX(30px);opacity:0} }
  @keyframes fire   { 0%{transform:translateY(0) scale(1);opacity:1} 100%{transform:translateY(-60px) scale(0.1);opacity:0} }
  @keyframes bubble { 0%{transform:translateY(0) scale(0.5);opacity:0.8} 100%{transform:translateY(-120px) scale(1.2);opacity:0} }
  @keyframes spark  { 0%{transform:translate(0,0) scale(1);opacity:1} 100%{transform:translate(var(--tx),var(--ty)) scale(0);opacity:0} }
  @keyframes glow-pulse { 0%,100%{opacity:0.4;transform:scale(1)} 50%{opacity:1;transform:scale(1.3)} }
  @keyframes magic  { 0%{transform:rotate(0deg) translateX(40px) rotate(0deg) scale(1);opacity:1} 100%{transform:rotate(360deg) translateX(40px) rotate(-360deg) scale(0);opacity:0} }
  @keyframes ocean-wave { 0%,100%{transform:scaleX(1) translateY(0)} 50%{transform:scaleX(1.05) translateY(-8px)} }

  .raindrop {
    position: absolute;
    width: 2px;
    height: 18px;
    background: linear-gradient(180deg, transparent, #a0d8ff);
    border-radius: 2px;
    animation: rain linear infinite;
  }
  .snowflake {
    position: absolute;
    width: 6px; height: 6px;
    background: white;
    border-radius: 50%;
    animation: snow ease-in infinite;
    box-shadow: 0 0 4px rgba(200,230,255,0.8);
  }
  .ember {
    position: absolute;
    border-radius: 50%;
    animation: fire ease-out infinite;
  }
  .bubble-p {
    position: absolute;
    border: 1.5px solid rgba(100,200,255,0.7);
    border-radius: 50%;
    background: rgba(100,200,255,0.08);
    animation: bubble ease-out infinite;
  }
  .sparkle {
    position: absolute;
    width: 4px; height: 4px;
    border-radius: 50%;
    animation: spark ease-out infinite;
  }
  .glow-orb {
    width: 60px; height: 60px;
    border-radius: 50%;
    animation: glow-pulse 2s ease-in-out infinite;
  }
  .magic-star {
    position: absolute;
    font-size: 12px;
    animation: magic linear infinite;
  }
  .wave-layer {
    position: absolute;
    bottom: 0;
    left: 0; right: 0;
    border-radius: 60% 60% 0 0;
    animation: ocean-wave ease-in-out infinite;
  }

  /* Module property table */
  .prop-table th { color: #00d4ff; }
  .module-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 14px; margin: 18px 0; }
  .module-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 16px;
    border-top: 2px solid var(--c, #00d4ff);
  }
  .module-card h5 { font-family: 'Fredoka One', cursive; font-size: 0.95rem; margin-bottom: 6px; color: var(--c, #00d4ff); }
  .module-card p  { font-size: 0.82rem; color: var(--muted); }
  .step-list { counter-reset: step; list-style: none; padding: 0; }
  .step-list li {
    counter-increment: step;
    display: flex;
    gap: 14px;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
    font-size: 0.95rem;
    color: #d4d4e8;
  }
  .step-list li::before {
    content: counter(step);
    display: flex; align-items: center; justify-content: center;
    width: 26px; height: 26px;
    background: linear-gradient(135deg, #00d4ff, #ff00aa);
    color: #0f0e17; font-weight: 900; font-size: 12px;
    border-radius: 50%; flex-shrink: 0; margin-top: 2px;
  }
  .fx-tag {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 6px;
    font-size: 11px;
    font-weight: 800;
    letter-spacing: 0.5px;
    margin: 2px;
  }