.c4-board {
  display: grid;
  grid-template-columns: repeat(var(--c4-cols, 7), 1fr);
  gap: 6px;
  width: 100%;
  max-width: 520px;
  margin: 0 auto;
  padding: 10px;
  border-radius: 16px;
  background: linear-gradient(160deg, rgba(37, 72, 138, 0.55), rgba(20, 40, 90, 0.75));
}

.c4-cell {
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: rgba(6, 12, 28, 0.7);
  color: #fff;
  font-weight: 800;
  font-size: clamp(0.7rem, 2.2vw, 1.1rem);
  cursor: pointer;
  transition: transform 0.08s ease;
}

.c4-cell:hover {
  transform: scale(1.05);
}

.c4-cell--p {
  background: radial-gradient(circle at 35% 30%, #9be7ff, #2b8fd6);
  color: #08243f;
}

.c4-cell--a {
  background: radial-gradient(circle at 35% 30%, #ffd59e, #e07b2c);
  color: #3a1e08;
}