.chess {
  max-width: 560px;
  --square-light: #c7d3ea;
  --square-dark: #5b7fd6;
  --square-selected: #ffd60a;
  --piece-white: #ffffff;
  --piece-black: #0d0d14;
}

.chess-board {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: 1.5rem;
}

.chess-square {
  position: relative;
  aspect-ratio: 1;
  min-width: 0;
  border: 0;
  padding: 0;
  font-size: clamp(1.4rem, 7vw, 2.6rem);
  line-height: 1;
  cursor: pointer;
}

.chess-square--light {
  background: var(--square-light);
}

.chess-square--dark {
  background: var(--square-dark);
}

.chess-square[data-color="w"] {
  color: var(--piece-white);
  text-shadow: 0 0 2px var(--piece-black), 0 0 2px var(--piece-black);
}

.chess-square[data-color="b"] {
  color: var(--piece-black);
}

.chess-square--last {
  box-shadow: inset 0 0 0 100px rgba(255, 214, 10, 0.3);
}

.chess-square--check {
  box-shadow: inset 0 0 0 100px rgba(255, 60, 60, 0.55);
}

.chess-square--selected {
  outline: 3px solid var(--square-selected);
  outline-offset: -3px;
}

.chess-square--target::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 28%;
  height: 28%;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  background: var(--piece-black);
  opacity: 0.35;
  pointer-events: none;
}

.chess-square--target[data-color]::after {
  width: 90%;
  height: 90%;
  background: none;
  border: 3px solid var(--piece-black);
  opacity: 0.4;
}

.chess-square:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: -3px;
}

.chess-square:disabled {
  cursor: default;
}


.chess-clock {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: 0 0 0.75rem;
  padding: 0.5rem 1rem;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--fg);
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
}

.chess-clock[data-clock="w"] {
  margin: 0.75rem 0 1.5rem;
}

.chess-clock span {
  color: var(--fg-muted);
  font-family: var(--font);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.chess-clock--active {
  border-color: var(--accent);
  color: var(--accent);
}

.chess-clock--low {
  border-color: var(--accent-dim);
}

.chess-clock[hidden] {
  display: none;
}

.chess-board-wrap {
  position: relative;
  margin-bottom: 0;
}

.chess-board-wrap .chess-board {
  margin-bottom: 0;
}

.chess-promotion {
  position: absolute;
  inset: 0;
  z-index: 10;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 1rem;
  background: rgba(13, 13, 20, 0.88);
  border-radius: var(--radius-sm);
  color: var(--fg);
}

.chess-promotion[hidden] {
  display: none;
}

.chess-promotion p {
  font-size: 1.1rem;
  font-weight: 700;
}

.chess-promotion-choices {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
}

.chess-promote {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
  min-width: 5rem;
  padding: 0.75rem 0.5rem;
  background: var(--square-light);
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 3rem;
  line-height: 1;
  cursor: pointer;
  transition: border-color 0.15s, opacity 0.15s;
}

.chess-promote span {
  color: var(--piece-black);
  font-size: 0.8rem;
  font-weight: 600;
}

.chess-promote:hover {
  border-color: var(--accent);
  opacity: 0.8;
}

.chess-promote:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.chess-promotion[data-color="w"] .chess-promote {
  color: var(--piece-white);
  text-shadow: 0 0 2px var(--piece-black), 0 0 2px var(--piece-black);
}

.chess-promotion[data-color="b"] .chess-promote {
  color: var(--piece-black);
}

.chess-hint {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.5rem;
  color: var(--fg);
  font-size: 0.9rem;
}

.chess-hint[hidden] {
  display: none;
}

.chess-hint ul {
  margin-top: 0.5rem;
  padding-left: 1.25rem;
  color: var(--fg-muted);
}

.chess--wide {
  max-width: 1040px;
}

.bh-game[hidden] {
  display: none;
}

.bh-boards {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}

.bh-board {
  min-width: 0;
}

.bh-title {
  margin-bottom: 0.5rem;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.bh-board .chess-square {
  font-size: clamp(1rem, 3.2vw, 2.1rem);
}

.bh-seat-name {
  padding: 0.4rem 1rem;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--fg);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.bh-seat-name--active {
  border-color: var(--accent);
  color: var(--accent);
}

.bh-seat {
  margin: 0.5rem 0;
}

.bh-reserve {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  min-height: 2.4rem;
  margin-top: 0.35rem;
}

.bh-reserve-empty {
  color: var(--fg-muted);
  font-size: 0.75rem;
}

.bh-reserve-piece {
  min-width: 2.4rem;
  padding: 0.15rem 0.5rem;
  background: var(--square-light);
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 1.4rem;
  line-height: 1.2;
  cursor: pointer;
  transition: border-color 0.15s, opacity 0.15s;
}

.bh-reserve-piece[data-color="w"] {
  color: var(--piece-white);
  text-shadow: 0 0 2px var(--piece-black), 0 0 2px var(--piece-black);
}

.bh-reserve-piece[data-color="b"] {
  color: var(--piece-black);
}

.bh-reserve-piece:hover:not(:disabled) {
  border-color: var(--accent);
}

.bh-reserve-piece:disabled {
  cursor: default;
  opacity: 0.7;
}

.bh-reserve-piece--selected {
  border-color: var(--square-selected);
  box-shadow: 0 0 0 2px var(--square-selected);
}

.bh-reserve-piece:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

.bh-board-status {
  min-height: 2.6em;
  font-size: 0.85rem;
  color: var(--fg);
}

@media (max-width: 820px) {
  .bh-boards {
    grid-template-columns: minmax(0, 1fr);
  }

  .bh-board {
    max-width: 480px;
    margin: 0 auto;
    width: 100%;
  }

  .bh-board .chess-square {
    font-size: clamp(1.2rem, 7vw, 2.4rem);
  }
}

.chess-cpu-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem 1rem;
  margin-bottom: 0.5rem;
}

.chess-cpu-row span {
  flex: 1 1 14rem;
  color: var(--fg-muted);
  font-size: 0.9rem;
}