.gomoku-app {
  max-width: 720px;
  margin: 0 auto;
  color: #202124;
}

.game-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
}

.game-header h1 {
  margin-bottom: 6px;
}

.game-header p,
.game-note {
  color: #61666d;
}

.home-link {
  white-space: nowrap;
  margin-top: 8px;
}

.game-controls {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin: 22px 0 12px;
}

.game-controls select,
.game-controls button {
  min-height: 38px;
  box-sizing: border-box;
  border: 1px solid #aeb4bc;
  border-radius: 6px;
  padding: 7px 12px;
  background: #fff;
  color: #202124;
  font: inherit;
}

.game-controls button {
  cursor: pointer;
}

.game-controls button:disabled,
.game-controls select:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

.game-status {
  min-height: 24px;
  margin: 12px 0;
  font-weight: 600;
}

.board-wrap {
  width: min(92vw, 600px);
  margin: 18px auto;
}

.gomoku-board {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  width: 100%;
  aspect-ratio: 1;
  box-sizing: border-box;
  border: 2px solid #55442e;
  background-color: #d8aa5c;
  background-image:
    linear-gradient(
      to right,
      transparent calc(50% - 0.5px),
      rgba(62, 46, 27, 0.68) calc(50% - 0.5px),
      rgba(62, 46, 27, 0.68) calc(50% + 0.5px),
      transparent calc(50% + 0.5px)
    ),
    linear-gradient(
      to bottom,
      transparent calc(50% - 0.5px),
      rgba(62, 46, 27, 0.68) calc(50% - 0.5px),
      rgba(62, 46, 27, 0.68) calc(50% + 0.5px),
      transparent calc(50% + 0.5px)
    );
  background-size: calc(100% / 9) calc(100% / 9);
}

.gomoku-cell {
  position: relative;
  display: grid;
  place-items: center;
  aspect-ratio: 1;
  border: 0;
  padding: 0;
  background: transparent;
  cursor: pointer;
}

.gomoku-cell:disabled {
  cursor: default;
}

.gomoku-cell:focus-visible {
  outline: 3px solid #1769c2;
  outline-offset: -3px;
}

.stone {
  position: relative;
  width: 72%;
  height: 72%;
  border-radius: 50%;
  box-shadow:
    inset -3px -3px 5px rgba(0, 0, 0, 0.23),
    0 2px 3px rgba(0, 0, 0, 0.22);
}

.stone.black {
  background: #191919;
}

.stone.white {
  box-sizing: border-box;
  border: 1px solid #aaa;
  background: #f8f8f5;
}

.stone.last::after {
  content: "";
  position: absolute;
  width: 18%;
  height: 18%;
  top: 41%;
  left: 41%;
  border-radius: 50%;
  background: #d93025;
}

@media (max-width: 520px) {
  .game-header {
    display: block;
  }

  .game-controls {
    align-items: stretch;
  }

  .game-controls label,
  .game-controls select,
  .game-controls button {
    width: 100%;
  }
}