.bingo-cell {
  aspect-ratio: 1;
  min-height: 0;
  overflow: hidden;
  word-break: break-word;
  background: var(--dark);
  border: 1.5px solid var(--border);
  border-radius: 9px;
  display: flex; align-items: center; justify-content: center;
  text-align: center;
  font-size: clamp(.3rem, 1.2vh, 1.8rem);
  /* font-size: 1.1cqh; */
  font-weight: 600;
  line-height: 1.25;
  color: var(--text-soft);
  padding: 2px;
  cursor: pointer;
  user-select: none;
  transition: border-color .15s, background .2s, color .15s, box-shadow .2s, transform .1s;
  position: relative;
}
.bingo-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
  background: rgba(30,41,59,.6);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 12px;
  backdrop-filter: blur(8px);
  box-shadow: 0 16px 48px rgba(0,0,0,.5),
              0 0 80px rgba(124,58,237,.08);
  width: 100%;
}
.bingo-col-header {
  height: 28px;
  display: flex; align-items: center; justify-content: center;
  font-size: .65rem; font-weight: 800;
  letter-spacing: .2em; color: var(--violet-lt);
}
.bingo-cell:hover:not(.free) {
  border-color: rgba(167,139,250,.4);
  color: var(--text);
  transform: scale(1.02);
}
.bingo-cell:active:not(.free) { transform: scale(.96); }

.bingo-cell.checked {
  background: linear-gradient(135deg, var(--violet-dk), var(--violet));
  border-color: var(--violet-lt);
  color: #fff;
  box-shadow: 0 0 14px rgba(124,58,237,.45);
}
.bingo-cell.free {
  background: linear-gradient(135deg, var(--amber), #F97316);
  border-color: transparent;
  color: #fff;
  font-weight: 800;
  cursor: default;
  box-shadow: 0 0 14px rgba(245,158,11,.3);
}

/* Winning line highlight */
.bingo-cell.winning {
  background: linear-gradient(135deg, #6D28D9, var(--violet-lt));
  border-color: #fff;
  color: #fff;
  box-shadow: 0 0 0 2px rgba(255,255,255,.25),
              0 0 20px rgba(167,139,250,.6);
  animation: winPulse 1.4s ease infinite;
}
@keyframes winPulse {
  0%, 100% { box-shadow: 0 0 0 2px rgba(255,255,255,.2), 0 0 16px rgba(167,139,250,.5); }
  50%       { box-shadow: 0 0 0 3px rgba(255,255,255,.4), 0 0 28px rgba(167,139,250,.8); }
}

/* Cell check bounce */
@keyframes cellBounce {
  0%   { transform: scale(1); }
  35%  { transform: scale(.87); }
  65%  { transform: scale(1.07); }
  100% { transform: scale(1); }
}
.bingo-cell.bouncing { animation: cellBounce .22s ease; }