:root {
    --cyan: #00f5ff;
    --cyan-dim: #00b4c8;
    --cyan-dark: #003d47;
    --bg: #020c10;
    --panel: rgba(0,245,255,0.04);
    --border: rgba(0,245,255,0.18);
    --border-bright: rgba(0,245,255,0.5);
    --text: #c8eef2;
    --text-dim: #8ecfdb;
    --amber: #ffb700;
    --font-mono: 'Space Mono', monospace;
    --font-display: 'Chakra Petch', sans-serif;
    --font-body: 'Exo 2', sans-serif;
  }

  *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  img { max-width: 100%; height: auto; display: block; }
  html { scroll-behavior: smooth; overflow-x: hidden; }

  body {
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-body);
    font-size: 16px;
    overflow-x: hidden;
    cursor: crosshair;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
  }

  /* HOLOLINKY */
  body::after {
    content: '';
    position: fixed; inset: 0; z-index: 9999; pointer-events: none;
    background: repeating-linear-gradient(
      0deg, transparent, transparent 2px,
      rgba(0,0,0,0.07) 2px, rgba(0,0,0,0.07) 4px
    );
  }

  /* HVĚZDIČKYYY */
  #starfield {
    position: fixed; inset: 0; z-index: 0; pointer-events: none;
    background:
      radial-gradient(ellipse 80% 60% at 50% 0%, rgba(0,80,120,0.3) 0%, transparent 70%),
      var(--bg);
  }
  #starfield canvas { position: absolute; inset: 0; }

  /* HUD MŘÍŽKA */
  #hud-grid {
    position: fixed; inset: 0; z-index: 0; pointer-events: none;
    background-image:
      linear-gradient(rgba(0,245,255,0.022) 1px, transparent 1px),
      linear-gradient(90deg, rgba(0,245,255,0.022) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, rgba(0,0,0,0.6) 0%, transparent 100%);
    -webkit-mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, rgba(0,0,0,0.6) 0%, transparent 100%);
  }

  /* SVATOZÁŘ KURZORU */
  #cursor-glow {
    position: fixed; pointer-events: none; z-index: 9998;
    width: 280px; height: 280px; border-radius: 50%;
    background: radial-gradient(circle, rgba(0,245,255,0.045) 0%, transparent 70%);
    transform: translate(-50%, -50%);
  }

  .corner-tl, .corner-br {
    position: fixed; width: 36px; height: 36px; pointer-events: none; z-index: 999;
  }
  .corner-tl { top: 14px; left: 14px;
    border-top: 1px solid var(--cyan-dim); border-left: 1px solid var(--cyan-dim); }
  .corner-br { bottom: 14px; right: 14px;
    border-bottom: 1px solid var(--cyan-dim); border-right: 1px solid var(--cyan-dim); }

  /* NAV */
  nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    display: flex; align-items: center; justify-content: space-between;
    flex-wrap: nowrap; overflow: hidden;
    padding: 0 3rem; height: 56px;
    background: rgba(2,12,16,0.9);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--border);
  }
  .nav-back {
    font-family: var(--font-mono); font-size: 0.75rem;
    letter-spacing: 0.15em; color: var(--text-dim);
    text-decoration: none; text-transform: uppercase;
    transition: color 0.2s;
    display: flex; align-items: center; gap: 0.5rem;
  }
  .nav-back::before { content: '←'; color: var(--cyan); }
  .nav-back:hover { color: var(--cyan); }
  .nav-label {
    font-family: var(--font-mono); font-size: 0.68rem;
    letter-spacing: 0.25em; color: var(--cyan-dim); text-transform: uppercase;
  }
  .nav-status-wip {
    font-family: var(--font-mono); font-size: 0.7rem;
    color: var(--amber); letter-spacing: 0.1em;
    display: flex; align-items: center; gap: 0.4rem;
    white-space: nowrap;
  }
  .nav-status-wip .wip-icon {
    display: inline-flex; align-items: center; justify-content: center;
    width: 1em; height: 1em;
    animation: wip-spin 3s linear infinite;
    transform-origin: 50% 50%;
    flex-shrink: 0;
  }
  @keyframes wip-spin { to { transform: rotate(360deg); } }

  /* HLAVNÍ OBSAH */
  .container {
    position: relative; z-index: 1;
    display: flex; flex-direction: column;
    align-items: center; justify-content: center;
    text-align: center;
    padding: 2rem;
    max-width: 600px;
    opacity: 0; animation: fadeUp 0.8s 0.3s forwards;
  }

  .error-code {
    font-family: var(--font-mono); font-size: 0.7rem;
    letter-spacing: 0.3em; color: var(--amber);
    text-transform: uppercase; margin-bottom: 2rem;
    display: flex; align-items: center; gap: 0.8rem;
  }
  .error-code::before, .error-code::after {
    content: ''; flex: 1; height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,183,0,0.3), transparent);
  }

  .title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 6vw, 3.5rem);
    font-weight: 700; color: #fff;
    letter-spacing: 0.08em; text-transform: uppercase;
    line-height: 1.1; margin-bottom: 1.5rem;
  }
  .title .accent { color: var(--cyan); }

  .subtitle {
    font-family: var(--font-mono); font-size: 0.8rem;
    letter-spacing: 0.12em; color: var(--text-dim);
    text-transform: uppercase; line-height: 1.8;
    margin-bottom: 2.5rem;
  }

  /* animované "tečky" k načítání */
  .loading-dots {
    display: flex; gap: 0.5rem; justify-content: center;
    margin-bottom: 3rem;
  }
  .loading-dots span {
    width: 6px; height: 6px; border-radius: 50%;
    background: var(--cyan-dark); border: 1px solid var(--cyan-dim);
    animation: dot-pulse 1.4s infinite ease-in-out;
  }
  .loading-dots span:nth-child(1) { animation-delay: 0s; }
  .loading-dots span:nth-child(2) { animation-delay: 0.2s; }
  .loading-dots span:nth-child(3) { animation-delay: 0.4s; }
  .loading-dots span:nth-child(4) { animation-delay: 0.6s; }
  .loading-dots span:nth-child(5) { animation-delay: 0.8s; }
  @keyframes dot-pulse {
    0%, 80%, 100% { background: var(--cyan-dark); border-color: var(--cyan-dim); }
    40% { background: var(--cyan); border-color: var(--cyan); box-shadow: 0 0 8px var(--cyan); }
  }

  .btn {
    font-family: var(--font-mono); font-size: 0.75rem;
    letter-spacing: 0.15em; text-decoration: none; text-transform: uppercase;
    padding: 0.75rem 1.8rem; border: 1px solid var(--cyan); color: var(--cyan);
    background: transparent; cursor: pointer;
    transition: background 0.2s, color 0.2s, box-shadow 0.2s;
    clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
    display: inline-block;
  }
  .btn:hover { background: var(--cyan); color: var(--bg); box-shadow: 0 0 28px rgba(0,245,255,0.35); }

  @keyframes fadeUp {
    from { opacity: 0; transform: translateY(20px); }
    to   { opacity: 1; transform: none; }
  }

  @media (max-width: 600px) {
    nav { padding: 0 1rem; }
    .nav-label { display: none; }
  }