:root {
  --puzzle-ink: #f4f4f5;
  --puzzle-muted: #a1a1aa;
  --puzzle-line: #303036;
  --puzzle-card: #0b0b0d;
  --puzzle-accent: #ffffff;
  --puzzle-accent-dark: #d4d4d8;
  --queen-color: #050506;
  --knight-color: #303036;
  --board-light: #f4f4f5;
  --board-dark: #c7c7cc;
  --board-covered: #9f9fa6;
  --board-conflict: #ffffff;
  --board-uncovered: #68686f;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.queens-knights-page {
  background:
    linear-gradient(rgba(255, 255, 255, 0.018) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.018) 1px, transparent 1px),
    radial-gradient(circle at 50% -10rem, #1a1a1e 0, transparent 38rem),
    #050506;
  background-size: 4rem 4rem, 4rem 4rem, auto, auto;
  color: var(--puzzle-ink);
}

.puzzle-main {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: clamp(1.25rem, 4vw, 3rem) clamp(0.75rem, 3vw, 2rem) 3rem;
  text-align: left;
}

.puzzle-hero {
  margin-bottom: clamp(1.25rem, 3vw, 2rem);
  text-align: center;
}

.puzzle-hero__eyebrow {
  margin-bottom: 0.25rem;
  color: var(--puzzle-muted);
  font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.puzzle-hero h1 {
  margin: 0;
  font-size: clamp(2.2rem, 7vw, 4.25rem);
  font-weight: 650;
  letter-spacing: -0.04em;
}

.puzzle-hero > p:last-child {
  max-width: 38rem;
  margin: 0.55rem auto 0;
  color: var(--puzzle-muted);
  font-size: clamp(0.95rem, 2vw, 1.1rem);
}

.puzzle-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(16rem, 19rem);
  gap: clamp(1rem, 3vw, 2rem);
  align-items: start;
  width: 100%;
}

.game-card,
.rules-card {
  border: 1px solid var(--puzzle-line);
  border-radius: 0.4rem;
  background: var(--puzzle-card);
  box-shadow: 0 1rem 2.5rem rgba(0, 0, 0, 0.32);
}

.game-card {
  min-width: 0;
  padding: clamp(0.75rem, 3vw, 1.5rem);
}

.archive-nav {
  display: grid;
  grid-template-columns: auto minmax(9rem, 1fr) auto;
  gap: 0.65rem;
  align-items: end;
}

.archive-nav__button,
.puzzle-picker select,
.button {
  min-height: 2.75rem;
  border: 1px solid var(--puzzle-line);
  border-radius: 2px;
  font: inherit;
  font-size: 0.85rem;
}

.archive-nav__button {
  padding: 0.65rem 0.85rem;
  background: #111114;
  color: var(--puzzle-ink);
  cursor: pointer;
}

.archive-nav__button:hover:not(:disabled) {
  border-color: #71717a;
  background: #19191d;
}

.archive-nav__button:disabled,
.button:disabled,
.puzzle-picker select:disabled {
  cursor: not-allowed;
  opacity: 0.48;
}

.puzzle-picker label {
  display: block;
  margin: 0 0 0.25rem 0.1rem;
  color: var(--puzzle-muted);
  font-family: ui-monospace, "SFMono-Regular", Consolas, monospace;
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.puzzle-picker select {
  width: 100%;
  padding: 0.55rem 2rem 0.55rem 0.75rem;
  background: var(--puzzle-card);
  color: var(--puzzle-ink);
}

.archive-summary {
  margin: 0.55rem 0 0;
  color: var(--puzzle-muted);
  font-size: 0.7rem;
  text-align: center;
}

.puzzle-date-heading {
  margin: 1.25rem 0 0.8rem;
  font-size: clamp(1.15rem, 3vw, 1.45rem);
  text-align: center;
}

.piece-goals {
  display: flex;
  justify-content: center;
  gap: 0.65rem;
  margin-bottom: 0.85rem;
}

.piece-goal {
  display: flex;
  gap: 0.55rem;
  align-items: center;
  min-width: 8rem;
  padding: 0.45rem 0.75rem;
  border: 1px solid var(--puzzle-line);
  border-radius: 2px;
  background: #111114;
}

.piece-goal__symbol {
  padding: 0.18rem 0.28rem;
  border-radius: 2px;
  background: #e4e4e7;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.55rem;
  line-height: 1;
}

.piece-goal--queen .piece-goal__symbol {
  color: var(--queen-color);
}

.piece-goal--knight .piece-goal__symbol {
  color: var(--knight-color);
}

.piece-goal strong,
.piece-goal small {
  display: block;
  line-height: 1.1;
}

.piece-goal strong {
  font-size: 0.82rem;
}

.piece-goal small {
  margin-top: 0.12rem;
  color: var(--puzzle-muted);
  font-size: 0.62rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.puzzle-board {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  grid-template-rows: repeat(5, minmax(0, 1fr));
  gap: clamp(2px, 0.65vw, 5px);
  width: min(100%, 31rem);
  aspect-ratio: 1;
  margin: 0 auto;
  padding: clamp(4px, 1vw, 8px);
  border: 1px solid #55555d;
  border-radius: 0.35rem;
  background: #050506;
  box-shadow: 0 0.8rem 1.8rem rgba(0, 0, 0, 0.35);
}

.board-cell {
  display: grid;
  width: 100%;
  height: 100%;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
  place-items: center;
  border: 0;
  border-radius: clamp(1px, 0.45vw, 3px);
  background: var(--board-light);
  color: var(--puzzle-ink);
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(1.7rem, 9vw, 3.35rem);
  line-height: 1;
  cursor: pointer;
  transition: transform 120ms ease, box-shadow 120ms ease, background-color 160ms ease;
}

.board-cell--dark {
  background: var(--board-dark);
}

.board-cell:hover:not(:disabled) {
  z-index: 1;
  box-shadow: inset 0 0 0 3px #050506;
  transform: scale(0.96);
}

.board-cell:focus-visible,
.archive-nav__button:focus-visible,
.puzzle-picker select:focus-visible,
.button:focus-visible,
.rules-card summary:focus-visible {
  outline: 2px solid #ffffff;
  outline-offset: 3px;
}

.board-cell--queen {
  color: var(--queen-color);
}

.board-cell--knight {
  color: var(--knight-color);
}

.board-cell--fixed {
  box-shadow: inset 0 0 0 3px #050506;
  cursor: default;
  opacity: 1;
}

.board-cell--revealed:not(.board-cell--fixed) {
  box-shadow: inset 0 0 0 3px #56565e;
}

.board-cell--covered {
  background: var(--board-covered);
}

.board-cell--uncovered {
  background: var(--board-uncovered);
}

.board-cell--invalid {
  background:
    repeating-linear-gradient(135deg, #ffffff 0 7px, #b7b7bd 7px 14px);
  box-shadow: inset 0 0 0 4px #050506;
}

.board-legend {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.55rem 1rem;
  margin-top: 0.85rem;
  color: var(--puzzle-muted);
  font-size: 0.66rem;
}

.board-legend span {
  display: inline-flex;
  gap: 0.32rem;
  align-items: center;
}

.board-legend__swatch {
  width: 0.7rem;
  height: 0.7rem;
  border: 1px solid #71717a;
  border-radius: 0.16rem;
  background: var(--board-light);
}

.board-legend__swatch--given {
  box-shadow: inset 0 0 0 2px #050506;
}

.board-legend__swatch--covered {
  background: var(--board-covered);
}

.board-legend__swatch--conflict {
  border-color: #050506;
  background: repeating-linear-gradient(135deg, #ffffff 0 3px, #8d8d95 3px 6px);
}

.game-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.6rem;
  margin-top: 1.15rem;
}

.button {
  padding: 0.65rem 1rem;
  font-weight: 700;
  cursor: pointer;
}

.button--primary {
  border-color: var(--puzzle-accent);
  background: var(--puzzle-accent);
  color: #050506;
}

.button--primary:hover:not(:disabled) {
  background: var(--puzzle-accent-dark);
}

.button--secondary {
  background: #17171a;
  color: var(--puzzle-ink);
}

.button--quiet {
  border-color: transparent;
  background: transparent;
  color: var(--puzzle-muted);
}

.button--secondary:hover:not(:disabled),
.button--quiet:hover:not(:disabled) {
  background: #232328;
}

.game-status {
  min-height: 2.8rem;
  margin: 0.85rem 0 0;
  padding: 0.6rem 0.8rem;
  border: 1px solid var(--puzzle-line);
  border-radius: 2px;
  background: #111114;
  color: var(--puzzle-muted);
  font-size: 0.78rem;
  text-align: center;
}

.game-status[data-tone="success"] {
  border-color: #ffffff;
  background: #151518;
  color: #ffffff;
}

.game-status[data-tone="error"] {
  border-style: double;
  border-width: 3px;
  background: #151518;
  color: #ffffff;
}

.rules-card {
  padding: 1.25rem;
  font-size: 0.83rem;
}

.rules-card h2 {
  margin-bottom: 0.75rem;
  font-size: 1.35rem;
}

.rules-card ol {
  display: grid;
  gap: 0.65rem;
  margin: 0 0 1rem 1.2rem;
  padding: 0;
}

.rules-card li::marker {
  color: var(--puzzle-muted);
  font-weight: 800;
}

.rules-card details {
  padding-top: 0.9rem;
  border-top: 1px solid var(--puzzle-line);
}

.rules-card summary {
  color: var(--puzzle-ink);
  font-weight: 800;
  cursor: pointer;
}

.rules-card details p {
  margin: 0.7rem 0 0;
  color: var(--puzzle-muted);
  font-size: 0.75rem;
}

.rules-card__tip {
  margin: 1rem 0 0;
  padding: 0.8rem;
  border: 1px solid var(--puzzle-line);
  border-radius: 2px;
  background: #111114;
  color: var(--puzzle-muted);
  font-size: 0.72rem;
}

.queens-knights-page footer p {
  margin: 0;
}

.queens-knights-page footer a {
  color: inherit;
}

@media (max-width: 800px) {
  .puzzle-layout {
    grid-template-columns: minmax(0, 1fr);
  }

  .rules-card {
    width: min(100%, 40rem);
    margin: 0 auto;
  }
}

@media (max-width: 430px) {
  .puzzle-main {
    padding-right: 0.5rem;
    padding-left: 0.5rem;
  }

  .game-card {
    padding: 0.65rem;
    border-radius: 0.3rem;
  }

  .archive-nav {
    grid-template-columns: 1fr 1.35fr 1fr;
    gap: 0.35rem;
  }

  .archive-nav__button {
    padding-right: 0.35rem;
    padding-left: 0.35rem;
    font-size: 0.75rem;
  }

  .piece-goals {
    gap: 0.35rem;
  }

  .piece-goal {
    min-width: 0;
    flex: 1;
    padding: 0.4rem 0.55rem;
  }

  .game-actions .button {
    flex: 1 1 calc(50% - 0.3rem);
  }
}

@media (prefers-reduced-motion: reduce) {
  .board-cell {
    transition: none;
  }
}