*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  :root {
    --void: #030712;
    --gold: #c8a96e;
    --gold-dim: #8a7048;
    --ice: #7dd3fc;
    --ice-dim: #3b82f6;
    --violet: #a78bfa;
    --white: #f0f4ff;
    --muted: #8899bb;
    --card-bg: rgba(14,26,52,0.82);
    --border: rgba(167,139,250,0.15);
  }
  html { scroll-behavior: smooth; }
  body { font-family: 'Inter', sans-serif; background: var(--void); color: var(--white); min-height: 100vh; overflow-x: hidden; }

  /* NAV */
  nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 2.5rem; height: 64px;
    background: rgba(3,7,18,0.8); backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(167,139,250,0.15);
  }
  .nav-logo { font-family:'Orbitron',monospace; font-size:.9rem; font-weight:700; color:var(--white); letter-spacing:.08em; display:flex; align-items:center; gap:.7rem; text-decoration:none; }
  .nav-logo-icon { font-size:1.1rem; animation:spin-slow 20s linear infinite; display:inline-block; }

  .hero-photo { position:relative; z-index:2; margin-bottom:1.5rem; }
  .hero-photo img { width:130px; height:130px; border-radius:50%; object-fit:cover; object-position:center top; border:3px solid rgba(167,139,250,.5); box-shadow:0 0 40px rgba(167,139,250,.3), 0 0 0 6px rgba(167,139,250,.08); }
  @keyframes spin-slow { to { transform:rotate(360deg); } }
  .nav-links { display:flex; align-items:center; gap:2rem; list-style:none; }
  .nav-links a { font-size:.7rem; font-family:'Orbitron',monospace; letter-spacing:.1em; color:var(--muted); text-decoration:none; text-transform:uppercase; transition:color .2s; }
  .nav-links a:hover { color:var(--violet); }

  /* HERO */
  .hero { position:relative; height:85vh; min-height:500px; display:flex; align-items:center; justify-content:center; overflow:hidden; }
  .hero-bg { position:absolute; inset:0; background-image:url('https://upload.wikimedia.org/wikipedia/commons/thumb/c/c2/Solar_sys8.jpg/1920px-Solar_sys8.jpg'); background-size:cover; background-position:center 30%; filter:brightness(.35) saturate(1.3); transform:scale(1.05); z-index:0; }
  .hero-glow { position:absolute; width:700px; height:700px; border-radius:50%; background:radial-gradient(circle,rgba(124,58,237,.14) 0%,transparent 70%); top:45%; left:50%; transform:translate(-50%,-55%); z-index:1; pointer-events:none; }
  .hero-overlay { position:absolute; inset:0; background:linear-gradient(to bottom,rgba(3,7,18,.25) 0%,rgba(3,7,18,.0) 35%,rgba(3,7,18,.85) 85%,rgba(3,7,18,1) 100%); z-index:1; }
  .hero-content { position:relative; z-index:2; text-align:center; padding:0 1.5rem; }
  .hero-eyebrow { font-family:'Orbitron',monospace; font-size:.62rem; letter-spacing:.4em; color:var(--violet); text-transform:uppercase; display:block; margin-bottom:1.2rem; }
  .hero-title { font-family:'Orbitron',monospace; font-size:clamp(2.4rem,6vw,5.2rem); font-weight:900; line-height:1.05; background:linear-gradient(135deg,#fff 0%,var(--violet) 50%,var(--gold) 100%); -webkit-background-clip:text; -webkit-text-fill-color:transparent; background-clip:text; margin-bottom:1rem; }
  .hero-sub { font-size:clamp(.9rem,2vw,1.1rem); color:var(--muted); font-weight:300; max-width:520px; margin:0 auto 2.5rem; line-height:1.7; }
  .hero-sub em { color:var(--gold); font-style:normal; }
  .hero-cta { display:inline-flex; align-items:center; gap:.6rem; background:rgba(167,139,250,.1); border:1px solid rgba(167,139,250,.35); color:var(--violet); font-family:'Orbitron',monospace; font-size:.72rem; letter-spacing:.15em; padding:.75rem 1.8rem; border-radius:2px; text-decoration:none; transition:all .3s; }
  .hero-cta:hover { background:rgba(167,139,250,.2); box-shadow:0 0 28px rgba(167,139,250,.3); transform:translateY(-2px); }
  .scroll-hint { position:absolute; bottom:2rem; left:50%; transform:translateX(-50%); z-index:2; display:flex; flex-direction:column; align-items:center; gap:.4rem; color:var(--muted); font-size:.6rem; letter-spacing:.2em; text-transform:uppercase; animation:bounce 2s infinite; }
  @keyframes bounce { 0%,100% { transform:translateX(-50%) translateY(0); } 50% { transform:translateX(-50%) translateY(7px); } }

  /* MAIN */
  main { position:relative; z-index:2; background:var(--void); padding:5rem 0 6rem; }
  .container { max-width:1300px; margin:0 auto; padding:0 2rem; }

  /* SEARCH */
  .search-section { text-align:center; margin-bottom:3.5rem; }
  .search-label { font-family:'Orbitron',monospace; font-size:.6rem; letter-spacing:.38em; color:var(--gold); text-transform:uppercase; display:block; margin-bottom:1.2rem; }
  .search-wrapper { position:relative; max-width:620px; margin:0 auto; }
  .search-icon { position:absolute; left:1.2rem; top:50%; transform:translateY(-50%); color:var(--muted); pointer-events:none; }
  #searchInput { width:100%; background:rgba(20,10,40,.9); border:1px solid rgba(167,139,250,.2); border-radius:3px; color:var(--white); font-family:'Inter',sans-serif; font-size:1rem; padding:1rem 2.5rem 1rem 3rem; outline:none; transition:border-color .3s,box-shadow .3s; }
  #searchInput::placeholder { color:var(--muted); }
  #searchInput:focus { border-color:rgba(167,139,250,.5); box-shadow:0 0 0 3px rgba(167,139,250,.08); }
  .search-clear { position:absolute; right:1rem; top:50%; transform:translateY(-50%); background:none; border:none; color:var(--muted); cursor:pointer; font-size:1rem; display:none; }
  .search-clear.visible { display:block; }
  #searchCount { margin-top:.85rem; font-size:.72rem; color:var(--muted); min-height:1.2em; font-family:'Orbitron',monospace; letter-spacing:.06em; }

  /* VIDEOS HEADER */
  .videos-header { display:flex; align-items:center; justify-content:space-between; margin-bottom:2rem; padding-bottom:1rem; border-bottom:1px solid var(--border); }
  .videos-title { font-family:'Orbitron',monospace; font-size:.9rem; font-weight:700; letter-spacing:.1em; text-transform:uppercase; color:var(--white); }
  .videos-count { font-family:'Orbitron',monospace; font-size:.6rem; letter-spacing:.1em; color:var(--gold); background:rgba(200,169,110,.08); border:1px solid rgba(200,169,110,.2); padding:.3rem .75rem; border-radius:2px; }

  /* GRID */
  .video-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(370px,1fr)); gap:1.5rem; }

  /* CARD */
  .video-card { background:var(--card-bg); border:1px solid var(--border); border-radius:4px; overflow:hidden; transition:transform .3s,border-color .3s,box-shadow .3s; }
  .video-card:hover { transform:translateY(-5px); border-color:rgba(167,139,250,.35); box-shadow:0 16px 48px rgba(0,0,0,.55); }
  .video-card.hidden { display:none; }
  .video-embed { position:relative; padding-bottom:56.25%; background:#000; }
  .video-embed iframe { position:absolute; inset:0; width:100%; height:100%; border:none; }
  .video-info { padding:1.2rem 1.4rem .9rem; }
  .video-title { font-size:.95rem; font-weight:600; color:var(--white); line-height:1.45; margin-bottom:.5rem; }
  .video-meta { font-size:.7rem; color:var(--muted); display:flex; align-items:center; gap:.5rem; margin-bottom:.75rem; flex-wrap:wrap; }
  .video-topics { font-size:.7rem; color:var(--muted); line-height:1.5; margin-bottom:1rem; font-style:italic; border-left:2px solid rgba(167,139,250,.25); padding-left:.75rem; }

  /* CHAPTERS */
  .chapters-toggle { width:100%; display:flex; align-items:center; justify-content:space-between; background:rgba(167,139,250,.06); border:1px solid rgba(167,139,250,.18); border-radius:2px; padding:.65rem .9rem; color:var(--violet); font-family:'Orbitron',monospace; font-size:.6rem; letter-spacing:.12em; text-transform:uppercase; cursor:pointer; transition:background .2s; }
  .chapters-toggle:hover { background:rgba(167,139,250,.12); }
  .chapters-toggle svg { transition:transform .3s; }
  .chapters-toggle.open svg { transform:rotate(180deg); }
  .chapters-list { display:none; }
  .chapters-list.open { display:block; }
  .chapter-item { display:flex; align-items:flex-start; gap:.75rem; padding:.65rem .9rem; border-bottom:1px solid rgba(167,139,250,.07); text-decoration:none; transition:background .2s; }
  .chapter-item:last-child { border-bottom:none; }
  .chapter-item:hover { background:rgba(167,139,250,.07); }
  .chapter-time { font-family:'Orbitron',monospace; font-size:.6rem; color:var(--gold); white-space:nowrap; padding-top:.12rem; min-width:38px; }
  .chapter-label { font-size:.78rem; color:var(--muted); line-height:1.4; transition:color .2s; }
  .chapter-item:hover .chapter-label { color:var(--white); }
  .chapter-play { margin-left:auto; color:var(--violet); opacity:0; transition:opacity .2s; flex-shrink:0; padding-top:.15rem; }
  .chapter-item:hover .chapter-play { opacity:1; }

  mark { background:rgba(200,169,110,.28); color:var(--gold); border-radius:2px; padding:0 2px; }

  .no-results { text-align:center; padding:4rem 2rem; display:none; }
  .no-results.visible { display:block; }
  .no-results h3 { font-family:'Orbitron',monospace; font-size:1rem; color:var(--muted); margin-bottom:.5rem; }
  .no-results p { font-size:.82rem; color:var(--gold-dim); }

  footer { text-align:center; padding:2.5rem; border-top:1px solid rgba(167,139,250,.1); font-size:.65rem; color:var(--muted); font-family:'Orbitron',monospace; letter-spacing:.1em; }

  @media (max-width:700px) {
    nav { padding:0 1.2rem; } .nav-links { display:none; }
    .container { padding:0 1rem; } .hero-title { font-size:2.2rem; }
    .video-grid { grid-template-columns:1fr; }
  }