.puzzle-app--dark {
  --bg-gradient: radial-gradient(1200px 800px at 20% -10%, #1a1f2b, #0f1115);
  --panel: #181b22;
  --panel-2: #1f232c;
  --line: #2c313c;
  --grid: #3a4150;
  --ink: #e8ecf3;
  --muted: #8b93a3;
  --accent: #6ea8fe;
  --green: #34d27b;
  --arc: #ffd166;
  --danger: #ff6b6b;
  --uncertain: #d4a3ff;
  --field-bg: #0e1218;
  --card-shadow: rgba(0, 0, 0, 0.35);
}

.puzzle-app--light {
  --bg-gradient: var(--clr-bg);
  --panel: var(--clr-surface);
  --panel-2: var(--clr-surface);
  --line: var(--clr-border);
  --grid: var(--clr-border);
  --ink: var(--clr-text);
  --muted: var(--clr-muted);
  --accent: var(--clr-accent);
  --green: #2f9e5b;
  --arc: #b8860b;
  --danger: #c0392b;
  --uncertain: #8a5fc7;
  --field-bg: var(--clr-bg);
  --card-shadow: rgba(26, 23, 20, 0.12);
}

.puzzle-app,
.puzzle-app *,
.puzzle-app *::before,
.puzzle-app *::after {
  box-sizing: border-box;
}

.puzzle-app {
  background: var(--bg-gradient);
  color: var(--ink);
  font: 14px/1.45 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  padding: 22px;
  border-radius: 16px;
}

.puzzle-app .wrap {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  flex-wrap: wrap;
}

.puzzle-app .card {
  background: linear-gradient(180deg, var(--panel), var(--panel-2));
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 16px;
  box-shadow: 0 10px 30px var(--card-shadow);
}

.puzzle-app .controls {
  display: flex;
  gap: 18px;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.puzzle-app .controls label {
  color: var(--muted);
}

.puzzle-app input[type=number] {
  width: 64px;
  background: var(--field-bg);
  color: var(--ink);
  border: 1px solid var(--grid);
  border-radius: 8px;
  padding: 6px 8px;
  font-size: 14px;
}

.puzzle-app select {
  background: var(--field-bg);
  color: var(--ink);
  border: 1px solid var(--grid);
  border-radius: 8px;
  padding: 6px 8px;
  font-size: 14px;
}

.puzzle-app button.ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--grid);
  border-radius: 10px;
  padding: 8px 14px;
  cursor: pointer;
  font-weight: 600;
}

.puzzle-app button.ghost:hover {
  color: var(--ink);
  border-color: var(--accent);
}

.puzzle-app .hint {
  color: var(--muted);
  font-size: 12px;
}

.puzzle-app svg {
  display: block;
  touch-action: manipulation;
}

.puzzle-app .cell-hit {
  cursor: pointer;
  fill: transparent;
}

.puzzle-app .cell-hit:hover {
  stroke: var(--accent);
  stroke-width: 2.5;
}

.puzzle-app .panel-title {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--muted);
  margin: 0 0 10px;
}

.puzzle-app .total {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 6px;
}

.puzzle-app .total b {
  display: block;
  font-size: 30px;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
  word-break: break-all;
}

.puzzle-app .legend {
  margin-top: 4px;
  max-height: 340px;
  overflow: auto;
}

.puzzle-app .legrow {
  display: grid;
  grid-template-columns: 16px 1fr auto;
  gap: 8px;
  align-items: center;
  padding: 5px 0;
  border-bottom: 1px dashed var(--line);
}

.puzzle-app .sw {
  width: 14px;
  height: 14px;
  border-radius: 4px;
  border: 1px solid color-mix(in srgb, var(--ink) 25%, transparent);
}

.puzzle-app .legrow small {
  color: var(--muted);
}

.puzzle-app .legrow b {
  font-variant-numeric: tabular-nums;
}

.puzzle-app .warn {
  color: var(--danger);
  font-weight: 700;
}

.puzzle-app .ok {
  color: var(--green);
  font-weight: 700;
}

.puzzle-app .sidecol {
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: 330px;
}

/* running score banner, sits above the controls */
.puzzle-app .scorebar {
  display: flex;
  gap: 28px;
  align-items: baseline;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.puzzle-app .scorebar .big {
  font-size: 34px;
  font-weight: 800;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
  word-break: break-all;
}

.puzzle-app .scorebar .lbl {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--muted);
  display: block;
}

.puzzle-app .scorebar .val {
  font-size: 20px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

/* the three scores the next move could produce */
.puzzle-app .nextvals {
  display: flex;
  gap: 8px;
  margin-top: 8px;
  flex-wrap: wrap;
}

.puzzle-app .nv {
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
  border: 1px solid var(--grid);
  border-radius: 8px;
  padding: 4px 9px;
  background: var(--field-bg);
}

.puzzle-app .nv b {
  font-weight: 800;
  color: var(--ink);
}

.puzzle-app .nv .cnt {
  color: var(--muted);
}

.puzzle-app .nv.na {
  opacity: .4;
}

.puzzle-app .nv.na b {
  color: var(--muted);
  font-weight: 600;
}

.puzzle-app .chk {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  cursor: pointer;
  user-select: none;
  color: var(--ink);
  font-weight: 600;
}

.puzzle-app .chk input {
  width: 16px;
  height: 16px;
  accent-color: var(--accent);
  cursor: pointer;
}

.puzzle-app .chk.tower input {
  accent-color: var(--green);
}

.puzzle-app .problems {
  max-height: 200px;
  overflow: auto;
}

.puzzle-app .problem {
  color: var(--danger);
  font-size: 12px;
  padding: 4px 0;
  border-bottom: 1px dashed var(--line);
}

.puzzle-app .moves {
  max-height: 340px;
  overflow: auto;
}

.puzzle-app .mvrow {
  display: grid;
  grid-template-columns: 34px 52px 44px 1fr;
  gap: 6px;
  align-items: center;
  padding: 4px 4px;
  border-bottom: 1px dashed var(--line);
  cursor: pointer;
  font-size: 12px;
}

.puzzle-app .mvrow:hover {
  background: color-mix(in srgb, var(--accent) 10%, transparent);
}

.puzzle-app .mvrow .num {
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.puzzle-app .mvrow .sc {
  text-align: right;
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  word-break: break-all;
}

.puzzle-app .mvrow.rec {
  background: color-mix(in srgb, var(--accent) 7%, transparent);
}

.puzzle-app .mvrow.rec .num {
  color: var(--accent);
  font-weight: 800;
}

.puzzle-app .mvrow.bad {
  background: color-mix(in srgb, var(--danger) 10%, transparent);
}

.puzzle-app .mvrow.bad .sc {
  color: var(--danger);
}

.puzzle-app .up {
  color: var(--green);
}

.puzzle-app .down {
  color: var(--arc);
}

.puzzle-app .flat {
  color: var(--muted);
}

@media (max-width: 700px) {
  .puzzle-app .wrap {
    flex-direction: column;
  }

  .puzzle-app .sidecol {
    width: 100%;
  }
}