:root {
  --bg-deep: #06151a;
  --bg-mid: #0d2730;
  --panel: rgba(6, 25, 31, 0.82);
  --line: rgba(182, 244, 235, 0.14);
  --text: #ecfff7;
  --muted: #a9d3cf;
  --accent: #9ff3d2;
  --accent-2: #ffd778;
  --danger: #ff9f84;
  --tile: #12353d;
  --tile-edge: #25545f;
  --sand: #c8a46b;
  --rock: #5a6f78;
  --wood: #8e6847;
  --crab: #ff7a6d;
  --shell: #ffcad8;
  --mint: #8ef0c8;
  --sun: #ffd56a;
  --plum: #d3b2ff;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: "Trebuchet MS", "Gill Sans", sans-serif;
  background:
    radial-gradient(circle at 20% 0%, rgba(140, 231, 220, 0.22), transparent 32%),
    radial-gradient(circle at 80% 18%, rgba(255, 215, 120, 0.16), transparent 24%),
    linear-gradient(180deg, #0b2430 0%, var(--bg-mid) 35%, var(--bg-deep) 100%);
}

.shell {
  width: min(100%, 640px);
  margin: 0 auto;
  padding: 14px 14px 28px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.22);
  backdrop-filter: blur(10px);
}

.topnav {
  margin-bottom: 12px;
  text-align: center;
  color: var(--muted);
}

.topnav a {
  color: var(--accent);
  text-decoration: none;
}

.hero {
  padding: 18px 18px 16px;
  text-align: center;
}

.eyebrow {
  margin: 0;
  color: var(--accent-2);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-size: 0.72rem;
}

h1 {
  margin: 7px 0 6px;
  font-size: clamp(2rem, 8vw, 3.4rem);
  line-height: 0.95;
}

.subtitle,
.picker-copy,
.round-copy,
.message,
.notes p {
  color: var(--muted);
}

.subtitle {
  margin: 0 auto;
  max-width: 32rem;
}

.hud {
  margin-top: 12px;
  padding: 10px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
}

.hud > div,
.legend div,
.dir-picker button,
button,
.notes,
.controls-card,
.board-wrap {
  border-radius: 18px;
}

.hud > div {
  background: rgba(255, 255, 255, 0.04);
  padding: 10px 8px;
  text-align: center;
}

.label {
  display: block;
  margin-bottom: 4px;
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.controls-card,
.board-wrap,
.legend,
.notes {
  margin-top: 12px;
  padding: 14px;
}

.dir-picker {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
}

.dir-picker button,
button {
  border: 0;
  font: inherit;
  cursor: pointer;
  transition: transform 140ms ease, background 140ms ease, opacity 140ms ease;
}

.dir-picker button {
  background: #173f49;
  color: var(--text);
  padding: 12px 8px;
  font-size: 1.15rem;
  font-weight: 700;
}

.dir-picker button.active {
  background: linear-gradient(180deg, #8ef0c8, #53cbb4);
  color: #12353d;
  transform: translateY(-1px);
}

.picker-copy {
  margin: 0 0 10px;
  text-align: center;
}

.action-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  margin-top: 12px;
}

button {
  background: #275563;
  color: var(--text);
  padding: 12px 10px;
  font-weight: 700;
}

button.primary {
  background: linear-gradient(180deg, #ffd778, #ffb957);
  color: #21323c;
}

button.alt {
  background: #6a4151;
}

button.hidden {
  display: none;
}

button:disabled {
  opacity: 0.45;
  cursor: default;
  transform: none;
}

.board-head {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: flex-start;
  margin-bottom: 12px;
}

.board-head strong {
  display: block;
}

.round-copy,
.step-label,
.message,
.notes p {
  margin: 0;
}

.step-label {
  text-align: right;
  color: var(--accent-2);
  font-weight: 700;
}

.board {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 8px;
}

.cell {
  position: relative;
  aspect-ratio: 1;
  border-radius: 18px;
  overflow: hidden;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.02)),
    radial-gradient(circle at 25% 25%, rgba(162, 233, 223, 0.16), transparent 38%),
    var(--tile);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.cell::before {
  content: "";
  position: absolute;
  inset: 8%;
  border-radius: 14px;
  border: 1px dashed rgba(255, 255, 255, 0.06);
}

.cell.placeable {
  cursor: pointer;
}

.cell.placeable.active {
  outline: 2px solid rgba(159, 243, 210, 0.8);
  outline-offset: -2px;
}

.cell.pool-shell { background: linear-gradient(180deg, rgba(255,255,255,0.18), transparent), var(--shell); color: #563348; }
.cell.pool-mint { background: linear-gradient(180deg, rgba(255,255,255,0.16), transparent), var(--mint); color: #154635; }
.cell.pool-sun { background: linear-gradient(180deg, rgba(255,255,255,0.14), transparent), var(--sun); color: #5a4200; }
.cell.pool-plum { background: linear-gradient(180deg, rgba(255,255,255,0.18), transparent), var(--plum); color: #4c2a68; }

.cell.rock {
  background: linear-gradient(180deg, rgba(255,255,255,0.05), rgba(0,0,0,0.04)), var(--rock);
}

.cell.driftwood {
  background: linear-gradient(180deg, rgba(255,255,255,0.05), rgba(0,0,0,0.08)), var(--wood);
}

.layer,
.marker,
.creature,
.crab-unit,
.pool-glyph,
.block-glyph,
.coord {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  pointer-events: none;
}

.pool-glyph,
.block-glyph {
  font-size: clamp(1rem, 4vw, 1.4rem);
  opacity: 0.92;
}

.coord {
  inset: auto 6px 6px auto;
  width: auto;
  height: auto;
  font-size: 0.52rem;
  color: rgba(255, 255, 255, 0.42);
}

.marker {
  font-size: clamp(1rem, 5vw, 1.7rem);
  color: var(--accent);
  text-shadow: 0 0 12px rgba(159, 243, 210, 0.44);
}

.creature {
  font-size: clamp(1.2rem, 6vw, 1.8rem);
}

.creature.shell { filter: drop-shadow(0 0 8px rgba(255, 202, 216, 0.5)); }
.creature.mint { filter: drop-shadow(0 0 8px rgba(142, 240, 200, 0.5)); }
.creature.sun { filter: drop-shadow(0 0 8px rgba(255, 213, 106, 0.46)); }
.creature.plum { filter: drop-shadow(0 0 8px rgba(211, 178, 255, 0.5)); }

.crab-unit {
  font-size: clamp(1rem, 4vw, 1.45rem);
  color: var(--crab);
  text-shadow: 0 0 8px rgba(255, 122, 109, 0.4);
}

.legend {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  color: var(--muted);
}

.legend div {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  background: rgba(255, 255, 255, 0.04);
}

.swatch {
  display: inline-block;
  width: 14px;
  height: 14px;
  border-radius: 999px;
  flex: 0 0 auto;
}

.swatch.pool.shell { background: var(--shell); }
.swatch.pool.mint { background: var(--mint); }
.swatch.pool.sun { background: var(--sun); }
.swatch.pool.plum { background: var(--plum); }
.swatch.block.rock { background: var(--rock); }
.swatch.block.wood { background: var(--wood); }
.swatch.crab { background: var(--crab); }
.swatch.arrow { background: var(--accent); }

.notes {
  display: grid;
  gap: 10px;
}

.notes button {
  width: 100%;
}

@media (max-width: 560px) {
  .hud {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .action-row {
    grid-template-columns: 1fr;
  }

  .board-head {
    flex-direction: column;
  }

  .step-label {
    text-align: left;
  }
}