:root{
      --bg:#0b1020;
      --card:#111a33;
      --muted:#a9b4d0;
      --text:#e9eefc;
      --brand:#7c5cff;
      --brand2:#22c1c3;
      --line:rgba(255,255,255,.08);
      --shadow: 0 18px 50px rgba(0,0,0,.45);
      --radius:18px;
    }
    *{box-sizing:border-box}
    body{
      margin:0;
      font-family: system-ui, -apple-system, Segoe UI, Roboto, "Noto Sans KR", Arial, sans-serif;
      color:var(--text);
      background:
        radial-gradient(1200px 600px at 10% 10%, rgba(124,92,255,.25), transparent 60%),
        radial-gradient(900px 500px at 90% 20%, rgba(34,193,195,.18), transparent 55%),
        linear-gradient(180deg, #070a14, var(--bg));
      min-height:100vh;
    }
    a{color:inherit; text-decoration:none}
    .container{max-width:1080px; margin:0 auto; padding:24px}
    header{
      position:sticky; top:0; z-index:50;
      backdrop-filter: blur(10px);
      background: rgba(7,10,20,.55);
      border-bottom:1px solid var(--line);
    }
    .nav{
      display:flex; align-items:center; justify-content:space-between;
      gap:16px;
      padding:14px 24px;
      max-width:1080px; margin:0 auto;
    }
    .logo{
      display:flex; align-items:center; gap:10px;
      font-weight:800; letter-spacing:-.3px;
    }
    .logo-badge{
      width:34px; height:34px; border-radius:12px;
      background: linear-gradient(135deg, var(--brand), var(--brand2));
      box-shadow: 0 10px 30px rgba(124,92,255,.25);
    }
    .nav-links{display:flex; gap:14px; flex-wrap:wrap}
    .nav-links a{
      padding:8px 10px; border-radius:12px;
      color:var(--muted);
      border:1px solid transparent;
    }
    .nav-links a:hover{
      color:var(--text);
      border-color:var(--line);
      background: rgba(255,255,255,.03);
    }
    .hero{
      padding:52px 0 18px;
      display:grid;
      grid-template-columns: 1.2fr .8fr;
      gap:22px;
      align-items:stretch;
    }
    @media (max-width: 900px){
      .hero{grid-template-columns:1fr}
    }
    .card{
      background: rgba(17,26,51,.72);
      border:1px solid var(--line);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
    }
    .hero-main{padding:28px}
    .pill{
      display:inline-flex; align-items:center; gap:8px;
      padding:8px 12px;
      border-radius:999px;
      border:1px solid var(--line);
      color:var(--muted);
      background: rgba(255,255,255,.03);
      font-size:13px;
    }
    h1{
      margin:14px 0 10px;
      font-size:44px;
      line-height:1.05;
      letter-spacing:-1px;
    }
    @media (max-width: 540px){ h1{font-size:34px} }
    .sub{
      color:var(--muted);
      font-size:16px;
      line-height:1.65;
      margin:0 0 18px;
    }
    .cta-row{display:flex; gap:10px; flex-wrap:wrap}
    .btn{
      display:inline-flex; align-items:center; justify-content:center;
      gap:10px;
      padding:11px 14px;
      border-radius:14px;
      border:1px solid var(--line);
      cursor:pointer;
      font-weight:700;
      transition: transform .08s ease, background .2s ease, border-color .2s ease;
      user-select:none;
    }
    .btn:hover{transform: translateY(-1px)}
    .btn.primary{
      background: linear-gradient(135deg, rgba(124,92,255,.95), rgba(34,193,195,.75));
      border-color: transparent;
    }
    .btn.ghost{
      background: rgba(255,255,255,.03);
      color:var(--text);
    }
    .hero-side{
      padding:18px;
      display:flex;
      flex-direction:column;
      gap:12px;
    }
    .mini{
      padding:16px;
      border-radius:16px;
      border:1px solid var(--line);
      background: rgba(255,255,255,.03);
    }
    .mini h3{margin:0 0 8px; font-size:16px}
    .mini p{margin:0; color:var(--muted); line-height:1.6; font-size:14px}
    .grid{
      display:grid;
      grid-template-columns: repeat(3, 1fr);
      gap:14px;
      padding: 14px 0;
    }
    @media (max-width: 900px){ .grid{grid-template-columns:1fr} }
    .feature{padding:18px}
    .feature .icon{
      width:42px; height:42px; border-radius:16px;
      display:grid; place-items:center;
      background: rgba(124,92,255,.15);
      border:1px solid var(--line);
      margin-bottom:10px;
      font-size:18px;
    }
    .feature h3{margin:0 0 6px}
    .feature p{margin:0; color:var(--muted); line-height:1.65}
    section{padding:22px 0}
    .section-title{
      display:flex; align-items:flex-end; justify-content:space-between; gap:14px;
      margin-bottom:12px;
    }
    .section-title h2{margin:0; font-size:22px; letter-spacing:-.4px}
    .section-title span{color:var(--muted); font-size:14px}
    .timeline{display:grid; gap:12px}
    .item{
      padding:16px;
      border-radius:16px;
      border:1px solid var(--line);
      background: rgba(255,255,255,.03);
      display:flex; gap:12px; align-items:flex-start;
    }
    .dot{
      width:12px; height:12px; border-radius:99px;
      margin-top:6px;
      background: linear-gradient(135deg, var(--brand), var(--brand2));
      box-shadow: 0 10px 25px rgba(124,92,255,.25);
      flex: 0 0 12px;
    }
    .item b{display:block; margin-bottom:4px}
    details{
      border:1px solid var(--line);
      background: rgba(255,255,255,.03);
      border-radius:16px;
      padding:14px 16px;
    }
    details + details{margin-top:10px}
    summary{cursor:pointer; font-weight:700}
    footer{
      padding:26px 0 40px;
      color:var(--muted);
      border-top:1px solid var(--line);
      margin-top:20px;
    }
    .toast{
      position: fixed;
      right: 18px;
      bottom: 18px;
      max-width: 320px;
      padding: 12px 14px;
      border-radius: 14px;
      border: 1px solid var(--line);
      background: rgba(17,26,51,.92);
      color: var(--text);
      box-shadow: var(--shadow);
      transform: translateY(20px);
      opacity: 0;
      pointer-events:none;
      transition: all .22s ease;
      font-size:14px;
      line-height:1.5;
    }
    .toast.show{
      transform: translateY(0);
      opacity: 1;
    }

    /* ===== TETRIS MODAL ===== */
    .modal-backdrop{
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,.55);
      display:none;
      align-items:center;
      justify-content:center;
      padding:18px;
      z-index: 999;
    }
    .modal-backdrop.show{ display:flex; }
    .modal{
      width:min(980px, 100%);
      border-radius: 22px;
      border:1px solid var(--line);
      background: rgba(17,26,51,.92);
      box-shadow: var(--shadow);
      overflow:hidden;
    }
    .modal-header{
      display:flex;
      align-items:center;
      justify-content:space-between;
      gap:12px;
      padding:14px 16px;
      border-bottom: 1px solid var(--line);
      background: rgba(255,255,255,.03);
    }
    .modal-header .title{
      display:flex; align-items:center; gap:10px;
      font-weight:800;
      letter-spacing:-.2px;
    }
    .modal-close{
      width:40px; height:40px;
      border-radius: 14px;
      border:1px solid var(--line);
      background: rgba(255,255,255,.03);
      color: var(--text);
      cursor:pointer;
      font-weight:900;
    }
    .modal-body{
      padding:16px;
      display:grid;
      grid-template-columns: 1fr 280px;
      gap:14px;
    }
    @media (max-width: 820px){
      .modal-body{ grid-template-columns: 1fr; }
    }
    .tetris-shell{
      border:1px solid var(--line);
      border-radius: 18px;
      background: rgba(255,255,255,.03);
      padding:14px;
      display:flex;
      align-items:center;
      justify-content:center;
      min-height: 520px;
    }
    canvas#tetris{
      width: 360px; /* CSS 사이즈 */
      height: 480px;
      image-rendering: pixelated;
      border-radius: 14px;
      border:1px solid rgba(255,255,255,.12);
      background: rgba(0,0,0,.35);
    }
    .sidepanel{
      border:1px solid var(--line);
      border-radius: 18px;
      background: rgba(255,255,255,.03);
      padding:14px;
      display:flex;
      flex-direction:column;
      gap:12px;
    }
    .stat{
      display:flex;
      justify-content:space-between;
      gap:10px;
      color: var(--muted);
      font-size: 14px;
      padding:10px 12px;
      border:1px solid var(--line);
      border-radius: 14px;
      background: rgba(0,0,0,.12);
    }
    .stat b{ color: var(--text); }
    .help{
      color: var(--muted);
      font-size: 13px;
      line-height: 1.6;
      border:1px solid var(--line);
      border-radius: 14px;
      padding: 12px;
      background: rgba(0,0,0,.12);
    }
    .side-actions{
      display:flex;
      gap:10px;
      flex-wrap:wrap;
    }
    .kbd{
      display:inline-block;
      padding:2px 8px;
      border-radius:10px;
      border:1px solid var(--line);
      background: rgba(255,255,255,.04);
      color: var(--text);
      font-weight:700;
      font-size:12px;
    }

    /* ===== CONTENT RICH SECTION ===== */
    .content-rich article h3 {
      margin-top: 24px;
      color: var(--brand2);
      font-size: 20px;
    }
    .content-rich article p {
      margin-bottom: 16px;
      font-size: 16px;
      color: var(--text);
      opacity: 0.9;
    }

    /* ===== CONTACT FORM ===== */
    .contact-card {
      padding: 32px;
      max-width: 640px;
      margin: 0 auto;
    }
    .form-group {
      margin-bottom: 20px;
    }
    .form-group label {
      display: block;
      margin-bottom: 8px;
      font-size: 14px;
      font-weight: 600;
      color: var(--muted);
    }
    .form-group input,
    .form-group textarea {
      width: 100%;
      padding: 14px;
      border-radius: 14px;
      border: 1px solid var(--line);
      background: rgba(255, 255, 255, 0.04);
      color: var(--text);
      font-family: inherit;
      font-size: 15px;
      transition: all 0.2s ease;
    }
    .form-group input:focus,
    .form-group textarea:focus {
      outline: none;
      border-color: var(--brand);
      background: rgba(255, 255, 255, 0.08);
      box-shadow: 0 0 0 4px rgba(124, 92, 255, 0.15);
    }
    .form-group input::placeholder,
    .form-group textarea::placeholder {
      color: rgba(255, 255, 255, 0.2);
    }