:root {
  color-scheme: dark;
  --bg: #07040f;
  --panel: #141025;
  --ink: #f4eaff;
  --muted: #b8aad4;
  --accent: #6efcff;
  --danger: #ff4f7a;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Trebuchet MS", "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at 20% 0%, #1c1632 0%, transparent 40%),
    radial-gradient(circle at 80% 0%, #112544 0%, transparent 42%),
    var(--bg);
  color: var(--ink);
  min-height: 100vh;
}

.app {
  max-width: 1180px;
  margin: 0 auto;
  padding: 18px;
  display: grid;
  gap: 14px;
}

.topbar h1 {
  margin: 6px 0 3px;
  font-size: clamp(1.4rem, 3vw, 2rem);
  letter-spacing: 0.03em;
}

.topbar p {
  margin: 0;
  color: var(--muted);
}

.back {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.95rem;
}

.panel {
  background: linear-gradient(180deg, #18122d, #0e0a1d);
  border: 1px solid #2d2450;
  border-radius: 14px;
  padding: 12px;
  box-shadow: 0 14px 30px rgba(2, 2, 10, 0.42);
}

.controls {
  display: grid;
  gap: 12px;
}

label {
  display: inline-block;
  margin-bottom: 6px;
  font-size: 0.9rem;
  color: var(--muted);
}

input[type="text"],
input[type="range"],
button {
  width: 100%;
}

input[type="text"] {
  background: #0f0b1d;
  border: 1px solid #3a2f66;
  color: var(--ink);
  border-radius: 10px;
  padding: 10px 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.row {
  display: flex;
  gap: 8px;
}

button {
  border: 0;
  border-radius: 10px;
  padding: 10px 12px;
  color: #fff;
  background: #31285a;
  cursor: pointer;
  font-weight: 700;
  letter-spacing: 0.04em;
}

button.primary { background: linear-gradient(90deg, #2d68ff, #6f6cff); }
button.ghost { background: #252040; }
button.danger { background: linear-gradient(90deg, #ca355c, #ff5480); }
button:hover { filter: brightness(1.08); }

.palette {
  display: grid;
  grid-template-columns: repeat(8, minmax(0, 1fr));
  gap: 8px;
}

.swatch {
  aspect-ratio: 1;
  border-radius: 8px;
  border: 2px solid transparent;
}

.swatch.active {
  border-color: #fff;
  box-shadow: 0 0 0 2px #1a1332;
}

.stats {
  color: var(--accent);
  font-weight: 700;
}

.board-wrap {
  overflow: hidden;
}

#board {
  width: 100%;
  height: auto;
  border-radius: 12px;
  display: block;
  background: #0b0a12;
  cursor: crosshair;
  touch-action: none;
}

.hint {
  margin: 8px 2px 2px;
  color: var(--muted);
  font-size: 0.9rem;
}

@media (min-width: 960px) {
  .app {
    grid-template-columns: 330px 1fr;
    align-items: start;
  }

  .topbar {
    grid-column: 1 / -1;
  }
}