:root {
  --bg: #050a24;
  --surface: #0b1338;
  --fg: #f4f6ff;
  --muted: #a3acd6;
  --rule: rgb(163 172 214 / 0.18);
  --accent: #3d6bff;
  --danger: #ff4d6d;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  background: var(--bg);
}

body {
  margin: 0;
  color: var(--fg);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-underline-offset: 0.2em;
}

.hero {
  position: relative;
  isolation: isolate;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  min-height: 100svh;
  overflow: hidden;
  padding: 24px 16px;
  text-align: center;
}

.hero::before {
  content: "";
  position: absolute;
  z-index: -2;
  inset: 0;
  background-image:
    linear-gradient(var(--rule) 1px, transparent 1px),
    linear-gradient(90deg, var(--rule) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse at 50% 40%, #000, transparent 70%);
}

.hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  top: -30vmin;
  left: 50%;
  width: 120vmin;
  height: 70vmin;
  border-radius: 50%;
  background: var(--accent);
  filter: blur(110px);
  opacity: 0.5;
  transform: translateX(-50%);
}

/* Stejná mřížka jako v pozadí, jen jasnější a viditelná kolem kurzoru. */
.spotlight {
  position: absolute;
  z-index: -1;
  inset: 0;
  background-image:
    linear-gradient(rgb(124 156 255 / 0.55) 1px, transparent 1px),
    linear-gradient(90deg, rgb(124 156 255 / 0.55) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(260px circle at var(--x, 50%) var(--y, 50%), #000, transparent);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s;
}

.spotlight.is-on {
  opacity: 1;
}

.tag {
  margin: 0 0 28px;
  padding: 7px 14px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: rgb(11 19 56 / 0.7);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(3rem, 11vw, 7.5rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1.05;
}

.lead {
  margin: 24px 0 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.3rem);
}

.scroll-hint {
  position: absolute;
  bottom: 32px;
  left: 50%;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 13px;
  text-decoration: none;
  transform: translateX(-50%);
  white-space: nowrap;
}

.scroll-hint:hover {
  color: var(--fg);
}

/* Výška sekce určuje, kolik se dá scrollovat, a tím délku hry. */
.game {
  height: calc(var(--track) + 100vh);
  height: calc(var(--track) + 100svh);
}

.game-stage {
  position: sticky;
  top: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
  max-width: 760px;
  height: 100vh;
  height: 100svh;
  margin: 0 auto;
  padding: 16px;
}

.game-hud {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 13px;
}

.game-hud strong {
  color: var(--fg);
  font-weight: 500;
}

.game-board {
  position: relative;
  flex: 1;
  min-height: 0;
  overflow: hidden;
  border: 1px solid var(--rule);
  border-radius: 20px;
  background: var(--surface);
}

.game-board canvas {
  position: absolute;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
}

.game-result {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 16px;
  background: rgb(5 10 36 / 0.6);
  text-align: center;
}

.game-verdict {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.game-score {
  font-size: clamp(2.5rem, 9vw, 4.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.game-best {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 13px;
}

.game-again {
  margin-top: 16px;
  padding: 12px 22px;
  border: 0;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}

.game-again:hover {
  background: #5a82ff;
}

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }

  @keyframes appear {
    from {
      opacity: 0;
      transform: translateY(12px);
    }
  }

  /* Pod .js, ať animace startující z opacity 0 nezávisí na načtení skriptu. */
  .js .tag,
  .js h1,
  .js .lead {
    animation: appear 0.8s cubic-bezier(0.2, 0.7, 0.2, 1) both;
  }

  .js h1 {
    animation-delay: 0.08s;
  }

  .js .lead {
    animation-delay: 0.16s;
  }

  .hero::after {
    animation: breathe 7s ease-in-out infinite alternate;
  }

  @keyframes breathe {
    to {
      opacity: 0.75;
      transform: translateX(-50%) scale(1.12);
    }
  }

  .scroll-arrow {
    display: inline-block;
    animation: bob 1.4s ease-in-out infinite alternate;
  }

  @keyframes bob {
    to {
      transform: translateY(5px);
    }
  }

  .game-result:not([hidden]) .game-score {
    animation: pop 0.5s cubic-bezier(0.2, 1.4, 0.4, 1) both;
  }

  @keyframes pop {
    from {
      opacity: 0;
      transform: scale(0.6);
    }
  }

  /* Průhledný text jen tam, kde gradient opravdu vykreslí; jinde zůstane plná barva. */
  @supports (background-clip: text) or (-webkit-background-clip: text) {
    h1 {
      background: linear-gradient(100deg, var(--fg) 40%, #9db4ff 50%, var(--fg) 60%) 0 0 / 300% 100%;
      -webkit-background-clip: text;
      background-clip: text;
      color: transparent;
    }

    .js h1 {
      animation:
        appear 0.8s cubic-bezier(0.2, 0.7, 0.2, 1) 0.08s both,
        shine 6s linear 1s infinite;
    }

    @keyframes shine {
      from {
        background-position: 100% 0;
      }

      to {
        background-position: 0% 0;
      }
    }
  }
}