:root {
  --bg: #07090d;
  --panel: #10151d;
  --tile: #181f2a;
  --tile-top: #212b39;
  --line: #2f3d52;
  --text: #f0f4fa;
  --accent: #64d2ff;
  --warn: #ff6d6d;
  --muted: #90a0b8;
  --shadow: rgba(0, 0, 0, 0.45);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Inter", "Segoe UI", Arial, sans-serif;
  background: radial-gradient(circle at 50% -20%, #1a2432 0%, var(--bg) 60%);
  color: var(--text);
  min-height: 100vh;
}

.app {
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: 0.8rem;
  padding: clamp(0.5rem, 1vw, 1rem);
}

.meta-rail {
  border: 1px solid var(--line);
  border-radius: 0.4rem;
  padding: 0.5rem 0.8rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: clamp(0.7rem, 1.1vw, 1rem);
  background: rgba(9, 13, 19, 0.65);
}

.board-shell {
  border: 1px solid var(--line);
  border-radius: 0.6rem;
  background: linear-gradient(180deg, #0b1016 0%, #06090d 100%);
  padding: clamp(0.5rem, 1vw, 1rem);
  box-shadow: 0 24px 48px var(--shadow);
  display: flex;
  align-items: center;
  justify-content: center;
}

.board {
  display: grid;
  gap: 0.22rem;
  width: 100%;
}

.flap-row {
  display: grid;
  grid-template-columns: repeat(var(--cols), minmax(8px, 1fr));
  gap: 0.22rem;
}

.tile {
  aspect-ratio: 0.72;
  border: 1px solid #273449;
  border-radius: 0.12rem;
  display: grid;
  place-items: center;
  color: var(--text);
  font-weight: 600;
  font-size: clamp(0.42rem, 1.2vw, 1.25rem);
  background:
    linear-gradient(180deg, var(--tile-top) 0 49.5%, #0d121a 49.5% 50.5%, var(--tile) 50.5% 100%);
  text-shadow: 0 1px 0 #000;
}

.tile.flipping {
  animation: flap 120ms ease-in-out;
}

.tile.accent {
  color: var(--accent);
}

.tile.warn {
  color: var(--warn);
}

.hud {
  position: fixed;
  right: 1rem;
  bottom: 1rem;
  width: min(450px, 90vw);
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  background: rgba(3, 6, 10, 0.92);
  color: var(--text);
  padding: 0.75rem;
  font-size: 0.84rem;
  z-index: 100;
}

.hud.hidden {
  display: none;
}

.hud h2 {
  margin: 0 0 0.6rem;
  font-size: 0.86rem;
  color: var(--accent);
  letter-spacing: 0.08em;
}

.hud dl {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.4rem;
  margin: 0;
}

.hud dt {
  color: var(--muted);
}

.hud dd {
  margin: 0;
  font-weight: 600;
}

.hud p {
  margin: 0.7rem 0 0;
  color: var(--muted);
  font-size: 0.74rem;
}

@keyframes flap {
  0% { transform: scaleY(1); filter: brightness(1); }
  50% { transform: scaleY(0.86); filter: brightness(1.35); }
  100% { transform: scaleY(1); filter: brightness(1); }
}

@media (prefers-reduced-motion: reduce) {
  .tile.flipping {
    animation: none;
  }
}