/* ==========================================================================
   Board — 19 × 19 Connect6 grid
   ========================================================================== */

.board-area {
  --board-max: 640px;
  width: 100%;
  max-width: var(--board-max);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 0;
}

.board-shell {
  display: grid;
  grid-template-columns: 18px minmax(0, 1fr) 18px;
  grid-template-rows: 18px minmax(0, 1fr) 18px;
  gap: 5px;
  width: 100%;
}

.coords {
  display: grid;
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.08em;
  color: var(--text-ghost);
  user-select: none;
}

.coords--top,
.coords--bottom {
  grid-template-columns: repeat(var(--board-size, 19), minmax(0, 1fr));
  align-items: center;
}

.coords--left,
.coords--right {
  grid-template-rows: repeat(var(--board-size, 19), minmax(0, 1fr));
  align-items: center;
}

.coords--top {
  align-items: end;
}

.coords--bottom {
  align-items: start;
}

.coords--left {
  justify-items: end;
}

.coords--right {
  justify-items: start;
}

.coord {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  opacity: 0.9;
}

.board {
  --board-size: 19;
  position: relative;
  display: grid;
  grid-template-rows: repeat(var(--board-size, 19), minmax(0, 1fr));
  aspect-ratio: 1 / 1;
  width: 100%;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  background:
    radial-gradient(120% 90% at 50% 0%, rgba(236, 231, 219, 0.045), transparent 55%),
    linear-gradient(158deg, #171d20 0%, #101416 48%, #0b0e10 100%);
  box-shadow:
    inset 0 0 0 1px rgba(0, 0, 0, 0.35),
    inset 0 0 60px rgba(0, 0, 0, 0.35),
    0 30px 80px -44px rgba(0, 0, 0, 0.95),
    0 0 0 1px rgba(227, 160, 67, 0.05);
  overflow: hidden;
  isolation: isolate;
}

.board::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  border-radius: inherit;
  box-shadow: inset 0 0 0 1px rgba(236, 231, 219, 0.03);
}

.board-row {
  display: grid;
  grid-template-columns: repeat(var(--board-size, 19), minmax(0, 1fr));
  min-height: 0;
}

.cell {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 0;
  min-height: 0;
  border-right: 1px solid rgba(236, 231, 219, 0.05);
  border-bottom: 1px solid rgba(236, 231, 219, 0.05);
  outline: none;
  cursor: default;
  -webkit-tap-highlight-color: transparent;
}

.board-row .cell:last-child {
  border-right: none;
}

.board-row:last-child .cell {
  border-bottom: none;
}

.cell::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(circle at 50% 42%, rgba(236, 231, 219, 0.07), transparent 68%);
  opacity: 0;
  transition: opacity var(--dur) var(--ease);
  z-index: 0;
}

.cell:hover::before {
  opacity: 1;
}

.cell:focus-visible {
  outline: 2px solid var(--amber-bright);
  outline-offset: -2px;
  border-radius: 2px;
  z-index: 5;
}

.cell--legal {
  cursor: pointer;
}

.board--interactive .cell--legal:hover::before {
  opacity: 0.95;
}

/* Star points ------------------------------------------------------------- */

.cell-star {
  position: absolute;
  z-index: 0;
  top: 50%;
  left: 50%;
  width: 4px;
  height: 4px;
  margin: -2px 0 0 -2px;
  border-radius: 50%;
  background: rgba(236, 231, 219, 0.28);
  pointer-events: none;
}

/* Stones ------------------------------------------------------------------ */

.piece {
  position: relative;
  z-index: 1;
  width: 86%;
  height: 86%;
  overflow: visible;
  filter: drop-shadow(0 2px 3px rgba(0, 0, 0, 0.55));
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

/* A stone must read against the board, so "black" is graphite with a light rim
   rather than pure black, and each seat keeps its own shape. */
.piece--black { --piece: #2b3338; --piece-bright: #6b7880; --piece-text: #f2efe6; }
.piece--white { --piece: #f2efe6; --piece-bright: #ffffff; --piece-text: #14181b; }

.piece .piece-shape {
  fill: var(--piece);
  stroke: rgba(0, 0, 0, 0.28);
  stroke-width: 2.5;
}

.piece--stone .piece-shape {
  fill: var(--piece);
  stroke-width: 3;
}

.piece--black.piece--stone .piece-shape {
  stroke: rgba(236, 231, 219, 0.42);
}

.piece--white.piece--stone .piece-shape {
  stroke: rgba(7, 9, 10, 0.5);
}

.piece-letter {
  font-family: var(--font-display);
  font-size: 42px;
  font-weight: 700;
  fill: var(--piece-text);
  letter-spacing: 0;
  dominant-baseline: middle;
}

.cell--pending .piece {
  opacity: 0.7;
}

.board--pending {
  pointer-events: none;
}

.board--pending::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 6;
  background: rgba(7, 9, 10, 0.24);
}

/* Legal move markers ------------------------------------------------------ */

.cell-marker {
  position: relative;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 62%;
  height: 62%;
  max-width: 26px;
  max-height: 26px;
  border-radius: 50%;
  border: 1.5px dashed rgba(227, 160, 67, 0.85);
  background: rgba(227, 160, 67, 0.18);
  color: var(--amber-bright);
  box-shadow: 0 0 14px -4px rgba(227, 160, 67, 0.55), inset 0 0 8px rgba(227, 160, 67, 0.12);
  animation: te-pulse 2600ms ease-in-out infinite;
}

.cell-marker svg {
  opacity: 1;
}

/* On a 19x19 Connect6 board almost every empty point is legal, so a cross on
   every point is pure noise. The marker only appears on the point under the
   pointer, or under keyboard focus, where it confirms the target.
   te-pulse animates opacity, and animations outrank normal declarations, so the
   idle state has to switch the animation off rather than just set opacity: 0. */
.cell-marker--hover {
  opacity: 0;
  animation: none;
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.board--interactive .cell--legal:hover .cell-marker--hover,
.board--interactive .cell--legal:focus-visible .cell-marker--hover {
  opacity: 1;
  animation: te-pulse 2600ms ease-in-out infinite;
}

.board--interactive .cell--legal:hover .cell-marker {
  background: rgba(227, 160, 67, 0.3);
  border-color: var(--amber-bright);
  color: var(--amber-bright);
  transform: scale(1.06);
}

/* Last stone -------------------------------------------------------------- */

.cell-last-mark {
  position: absolute;
  top: 4px;
  right: 4px;
  z-index: 4;
  width: 6px;
  height: 6px;
  border-radius: 2px;
  background: var(--amber-bright);
  box-shadow: 0 0 10px rgba(244, 188, 107, 0.85);
}

.cell--last::after {
  content: "";
  position: absolute;
  inset: 2px;
  border: 1px solid rgba(244, 188, 107, 0.34);
  border-radius: 3px;
  pointer-events: none;
  z-index: 3;
}

/* Winning line ------------------------------------------------------------ */

/* Each stone on the winning run gets a golden ring and a glow. A ring reads as
   "these five are a line" without needing to know the run's direction. */
.cell--win::before {
  opacity: 1;
  background: radial-gradient(circle at 50% 50%, rgba(244, 188, 107, 0.42), transparent 70%);
}

.cell--win::after {
  content: "";
  position: absolute;
  inset: 5%;
  border: 1.5px solid rgba(244, 188, 107, 0.8);
  border-radius: 50%;
  pointer-events: none;
  z-index: 2;
}

.cell--win .piece {
  filter: drop-shadow(0 0 7px rgba(244, 188, 107, 0.85));
}

/* Static diagram ---------------------------------------------------------- */

.board--static {
  --board-size: 9;
  width: 100%;
  max-width: 360px;
  border-radius: 5px;
  background: linear-gradient(160deg, #141a1d, #0b0e10);
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.3), var(--shadow-md);
}

.cell--static {
  border-color: rgba(236, 231, 219, 0.05);
}

.cell--static.cell--legal {
  background: rgba(227, 160, 67, 0.14);
  box-shadow: inset 0 0 0 1px rgba(227, 160, 67, 0.35);
}

.cell--static.cell--legal::after {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--amber);
  opacity: 0.8;
}

.stone-token {
  position: relative;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 74%;
  height: 74%;
  border-radius: 50%;
  font-family: var(--font-display);
  font-size: 9px;
  font-weight: 700;
  line-height: 1;
}

.stone-token--black {
  background: #1a1f22;
  border: 1px solid rgba(255, 253, 246, 0.24);
  color: #e8e3d7;
}

.stone-token--white {
  background: #ece7db;
  border: 1px solid rgba(0, 0, 0, 0.4);
  color: #1a1f22;
}

/* Hint -------------------------------------------------------------------- */

.board-hint {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  margin: 0;
  color: var(--text-ghost);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.05em;
  text-align: center;
}

.board-hint svg {
  opacity: 0.7;
}

/* Compact board (replay rail / inline) ------------------------------------ */

.board-area--compact {
  --board-max: 440px;
  gap: 6px;
}

.board-area--compact .board-hint {
  display: none;
}

@media (max-width: 720px) {
  .board-shell {
    grid-template-columns: 14px minmax(0, 1fr) 14px;
    grid-template-rows: 14px minmax(0, 1fr) 14px;
    gap: 3px;
  }

  .coords {
    font-size: 8px;
  }

  .piece-letter {
    font-size: 46px;
  }

  .cell-marker {
    max-width: 16px;
    max-height: 16px;
  }

  .cell-marker svg {
    width: 9px;
    height: 9px;
  }
}