:root {
      --bg-primary: #05070C;
      --bg-elevated: #0A0D14;
      --text-primary: #E8ECF2;
      --text-secondary: #B5BFD0;
      --text-muted: #8793A8;
      --text-whisper: #5E6678;
      --border: #161C2B;
      --border-bright: #232D40;
      --hairline: rgba(232, 236, 242, 0.12);
      --mint: #DFA43B;
      --ice: #1D4A78;
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      background: var(--bg-primary);
      color: var(--text-primary);
      font-family: 'Instrument Sans', system-ui, sans-serif;
      min-height: 100vh;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      overflow: hidden;
    }
    /* Luxury materiality layers */
    .ambient-glow, .vignette, .grain {
      position: fixed; inset: 0; pointer-events: none;
    }
    .ambient-glow {
      z-index: 0;
      background:
        radial-gradient(ellipse 70% 50% at 50% 30%, rgba(223,164,59, 0.04) 0%, transparent 55%),
        radial-gradient(ellipse 80% 60% at 50% 95%, rgba(29,74,120, 0.025) 0%, transparent 60%);
    }
    .vignette {
      z-index: 3;
      background: radial-gradient(ellipse at center, transparent 40%, rgba(0, 0, 0, 0.45) 100%);
    }
    .grain {
      z-index: 4;
      opacity: 0.05; mix-blend-mode: overlay;
      background-image: url("data:image/svg+xml;utf8,<svg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 1  0 0 0 0 1  0 0 0 0 1  0 0 0 0.5 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
    }
    nav, main, section, header, footer, .container { position: relative; z-index: 10; }
    @keyframes vortexSpin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }
    @keyframes breathe {
      0%, 100% { opacity: 0.18; transform: scale(1); }
      50%      { opacity: 0.32; transform: scale(1.06); }
    }
    .vortex-bg {
      position: fixed; top: 50%; left: 50%; transform: translate(-50%, -50%);
      width: 900px; height: 900px; pointer-events: none; z-index: 1;
      transition: opacity 0.6s ease;
    }
    .vortex-bg svg { width: 100%; height: 100%; overflow: visible; }
    .vortex-outer      { transform-origin: 400px 400px; animation: vortexSpin 120s linear infinite; }
    .vortex-outer-glow { transform-origin: 400px 400px; animation: vortexSpin 120s linear infinite; }
    .vortex-inner      { transform-origin: 400px 400px; animation: vortexSpin  90s linear infinite reverse; }
    .vortex-inner-glow { transform-origin: 400px 400px; animation: vortexSpin  90s linear infinite reverse; }
    .vortex-core {
      transform-origin: 400px 400px;
      animation: breathe 8s ease-in-out infinite;
    }
    #particles {
      position: fixed; top: 0; left: 0; width: 100%; height: 100%;
      pointer-events: none; z-index: 2;
    }
    .warp-whiteout {
      position: fixed; top: 0; left: 0; width: 100%; height: 100%;
      background: var(--bg-primary); opacity: 0; z-index: 11; pointer-events: none;
      transition: opacity 0.3s ease;
    }
    .warp-whiteout.active { opacity: 1; }
    .gate-card {
      position: relative; z-index: 10;
      background: rgba(16, 20, 28, 0.75);
      backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px);
      border: 1px solid var(--border-bright);
      border-radius: 20px;
      padding: 48px 40px;
      width: 100%; max-width: 420px;
      margin: 0 20px;
      text-align: center;
    }
    .logo { margin-bottom: 32px; display: flex; justify-content: center; }
    .logo svg { height: 36px; width: auto; }
    .gate-card h1 { font-size: 22px; font-weight: 600; letter-spacing: -0.02em; margin-bottom: 8px; }
    .gate-card p { font-size: 14px; color: var(--text-secondary); margin-bottom: 32px; line-height: 1.6; }
    .input-group { position: relative; margin-bottom: 16px; }
    .input-group input {
      width: 100%; padding: 14px 16px;
      font-family: 'IBM Plex Mono', monospace; font-size: 14px;
      background: rgba(8, 10, 15, 0.8);
      border: 1px solid var(--border-bright); border-radius: 10px;
      color: var(--text-primary); outline: none;
      transition: border-color 0.2s, box-shadow 0.2s;
    }
    .input-group input:focus { border-color: var(--mint); box-shadow: 0 0 0 3px rgba(223,164,59,0.1); }
    .input-group input.error { border-color: #EF4444; box-shadow: 0 0 0 3px rgba(239,68,68,0.1); }
    .error-msg { font-size: 13px; color: #EF4444; margin-bottom: 16px; display: none; font-weight: 500; }
    .error-msg.visible { display: block; }
    .btn-submit {
      width: 100%; padding: 14px 28px;
      font-family: 'Instrument Sans', sans-serif; font-size: 14px; font-weight: 600;
      background: var(--mint); color: #080A0F;
      border: none; border-radius: 10px; cursor: pointer; transition: all 0.2s;
    }
    .btn-submit:hover { transform: translateY(-1px); box-shadow: 0 8px 30px rgba(223,164,59,0.25); background: #2B5E90; }
    .btn-submit:disabled { opacity: 0.6; cursor: not-allowed; transform: none; box-shadow: none; }
    .back-link { display: inline-block; margin-top: 24px; font-size: 13px; color: var(--text-muted); text-decoration: none; transition: color 0.35s cubic-bezier(0.22, 1, 0.36, 1); }
    .back-link:hover { color: var(--text-secondary); }
    @keyframes shake { 0%,100%{transform:translateX(0)} 20%{transform:translateX(-8px)} 40%{transform:translateX(8px)} 60%{transform:translateX(-6px)} 80%{transform:translateX(6px)} }
    .shake { animation: shake 0.4s ease; }
    @keyframes fadeIn { from{opacity:0;transform:translateY(16px)} to{opacity:1;transform:translateY(0)} }
    .gate-card { animation: fadeIn 0.6s ease; transition: opacity 0.4s ease, transform 0.6s ease; }
    .gate-card.warp-out { opacity: 0; transform: translateY(-30px) scale(0.95); }

    /* Minimal footer for toggle */
    .page-footer {
      position: fixed;
      bottom: 18px;
      right: 18px;
      z-index: 20;
      display: flex;
      align-items: center;
      gap: 14px;
      font-family: 'IBM Plex Mono', monospace;
      font-size: 11px;
      color: var(--text-muted);
      letter-spacing: 0.12em;
      text-transform: uppercase;
    }
    @media (max-width: 520px) {
      .page-footer .foot-copy { display: none; }
    }


    /* Light mode palette */
    body.light {
      background: #FDFCFA;
      color: #111827;
    }
    body.light .page-footer { color: rgba(17,24,39,0.6); }
    body.light .ambient-glow {
      background:
        radial-gradient(ellipse 900px 600px at 15% 10%, rgba(29,74,120,0.04), transparent 60%),
        radial-gradient(ellipse 800px 500px at 85% 90%, rgba(223,164,59,0.03), transparent 60%);
    }
    body.light .vignette { background: radial-gradient(ellipse at center, transparent 40%, rgba(0,0,0,0.04) 100%); }
    body.light .grain { opacity: 0.015; }
    body.light .vortex-bg, body.light #particles { opacity: 0.4; mix-blend-mode: multiply; }
    body.light .gate-card {
      background: rgba(255,255,255,0.82);
      border-color: #DDE1E8;
    }
    body.light .gate-card h1 { color: #111827; }
    body.light .gate-card p { color: rgba(17,24,39,0.7); }
    body.light .input-group input {
      background: rgba(255,255,255,0.9);
      border-color: #DDE1E8;
      color: #111827;
    }
    body.light .input-group input:focus { border-color: #1D4A78; box-shadow: 0 0 0 3px rgba(29,74,120,0.12); }
    body.light .btn-submit { background: #1D4A78; color: #fff; }
    body.light .btn-submit:hover { background: #163A5F; box-shadow: 0 8px 30px rgba(29,74,120,0.22); }
    body.light .back-link { color: rgba(17,24,39,0.55); }
    body.light .back-link:hover { color: #1D4A78; }
    body.light .warp-whiteout { background: #FDFCFA; }