:root {
  --bg-1: #efe6d8;
  --bg-2: #d9cdb5;
  --ink: #2c2317;
  --grid-line: rgba(44, 35, 23, 0.25);
  --panel: rgba(255, 251, 242, 0.92);
  --accent: #7b3b1a;
  --c-yellow: #c9c347;
  --c-red: #c35b1e;
  --c-brown: #6a3a1d;
  --c-black: #1f1a16;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Palatino Linotype", "Book Antiqua", Georgia, serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top, rgba(255, 255, 255, 0.45), transparent 50%),
    radial-gradient(circle at 20% 30%, rgba(123, 59, 26, 0.08), transparent 55%),
    linear-gradient(145deg, var(--bg-1), var(--bg-2));
}

.stage {
  min-height: 100vh;
  display: grid;
  grid-template-columns: 1fr;
  position: relative;
  overflow: hidden;
}

.board-wrap {
  display: grid;
  place-items: center;
  padding: 2vh 2vw;
}

.board {
  width: min(96vmin, 96vh);
  height: min(96vmin, 96vh);
  display: grid;
  grid-template-columns: repeat(15, 1fr);
  grid-template-rows: repeat(14, 1fr);
  gap: 0;
  border: 2px solid rgba(44, 35, 23, 0.6);
  box-shadow: 0 20px 50px rgba(44, 35, 23, 0.18);
  background: rgba(255, 255, 255, 0.35);
}

.cell {
  display: grid;
  place-items: center;
  border: 1px solid var(--grid-line);
  font-size: clamp(12px, 1.8vmin, 20px);
  font-weight: 700;
  user-select: none;
  position: relative;
  transition: background-color 0.15s ease;
}

.cell[data-num]::after {
  content: attr(data-num);
  color: var(--ink);
  mix-blend-mode: multiply;
  text-shadow: 0 0 1px rgba(0, 0, 0, 0.35);
}

.cell.num-yellow::after {
  color: var(--c-yellow);
}

.cell.num-red::after {
  color: var(--c-red);
}

.cell.num-brown::after {
  color: var(--c-brown);
}

.cell.num-black::after {
  color: var(--c-black);
}

.cell.paint-yellow {
  background: color-mix(in srgb, var(--c-yellow) 60%, transparent);
}

.cell.paint-red {
  background: color-mix(in srgb, var(--c-red) 60%, transparent);
}

.cell.paint-brown {
  background: color-mix(in srgb, var(--c-brown) 60%, transparent);
}

.cell.paint-black {
  background: color-mix(in srgb, var(--c-black) 60%, transparent);
}

.hud {
  position: absolute;
  top: 2vh;
  left: 2vw;
  width: min(360px, 92vw);
  background: var(--panel);
  border: 1px solid rgba(44, 35, 23, 0.2);
  border-radius: 18px;
  padding: 16px 18px;
  box-shadow: 0 12px 30px rgba(44, 35, 23, 0.18);
  backdrop-filter: blur(6px);
}

.hud-header {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 12px;
}

.eyebrow {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin: 0 0 4px;
  color: var(--accent);
}

h1 {
  margin: 0 0 8px;
  font-size: 1.5rem;
}

.rules {
  font-size: 0.92rem;
  line-height: 1.4;
}

.rules ul {
  padding-left: 18px;
  margin: 8px 0 0;
}

.rules.is-hidden {
  display: none;
}

.hud.compact {
  width: auto;
  padding: 10px;
}

.hud.compact .hud-header {
  justify-content: flex-end;
}

.hud.compact .hud-header h1,
.hud.compact .eyebrow,
.hud.compact .rules,
.hud.compact .panel h2,
.hud.compact .controls,
.hud.compact .hint {
  display: none;
}

.hud.compact .panel {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.hud.compact .palette {
  grid-template-columns: 1fr;
}

.panel {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px dashed rgba(44, 35, 23, 0.2);
}

h2 {
  font-size: 1rem;
  margin: 0 0 10px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.palette {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
  margin-bottom: 12px;
}

.swatch {
  height: 32px;
  border-radius: 8px;
  border: 1px solid rgba(44, 35, 23, 0.2);
  cursor: pointer;
  position: relative;
}

.swatch.is-active::after {
  content: "✓";
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-weight: 700;
  color: var(--ink);
}

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

button {
  font-family: inherit;
  border-radius: 10px;
  padding: 8px 12px;
  border: none;
  cursor: pointer;
  font-weight: 600;
}

button.ghost {
  background: transparent;
  border: 1px solid rgba(44, 35, 23, 0.3);
  color: var(--ink);
}

button.solid {
  background: var(--accent);
  color: #fff9ef;
}

.hint {
  font-size: 0.82rem;
  margin: 10px 0 0;
  color: rgba(44, 35, 23, 0.75);
}

@media (max-width: 900px) {
  .board {
    width: min(98vmin, 98vh);
    height: min(98vmin, 98vh);
  }

  .hud {
    position: static;
    width: auto;
    margin: 0 4vw 4vh;
  }

  .stage {
    grid-template-rows: auto auto;
  }
}