/* Checkers — wooden board, glossy pieces, sliding moves. */
.levels { display: flex; gap: 8px; margin-bottom: 12px; flex-wrap: wrap; justify-content: center; }
.levels .tnz-btn { min-height: 40px; font-size: 14px; padding: 0 14px; }
.levels .tnz-btn.on { border-color: var(--primary); color: var(--primary); }
.ta { font-size: 13px; opacity: .9; }

.ck-score { display: flex; gap: 10px; width: min(100%, 420px); margin-bottom: 6px; }
.ck-side { flex: 1; display: flex; align-items: center; gap: 8px; background: var(--card); border: 2px solid transparent; border-radius: 12px; padding: 6px 10px; transition: border-color .2s, box-shadow .2s; }
.ck-side.turn { border-color: var(--gold); box-shadow: 0 0 12px #ffc53344; }
.ck-side .who { flex: 1; font-weight: 700; font-size: 14px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.ck-side b { font-size: 20px; }
.ck-side .ck-pc { position: relative; inset: auto; width: 22px; height: 22px; flex: none; display: inline-block; }
.ck-turn { font-weight: 700; min-height: 24px; margin: 4px 0 8px; text-align: center; }
.ck-turn.must { color: var(--gold); }

.ck-board {
  position: relative; width: min(100%, 420px); aspect-ratio: 1; padding: 8px; border-radius: 14px;
  display: grid; grid-template-columns: repeat(8, 1fr); grid-template-rows: repeat(8, 1fr);
  background: linear-gradient(160deg, #6b3d1c, #3d200c); box-shadow: 0 10px 28px #0009, inset 0 2px 0 #ffffff22;
  touch-action: manipulation;
}
.ck-sq { position: relative; }
.ck-sq.lt { background: #f1d9b0; }
.ck-sq.dk { background: #8a5a33; cursor: pointer; box-shadow: inset 0 0 6px #0005; }
.ck-sq.sel { background: #b07a3f; box-shadow: inset 0 0 0 3px var(--gold); }
.ck-sq.dest::after { content: ''; position: absolute; left: 50%; top: 50%; width: 30%; height: 30%; margin: -15% 0 0 -15%; border-radius: 50%; background: #ffc533aa; animation: ck-pulse 1.2s ease-in-out infinite; }
.ck-sq.from-last, .ck-sq.to-last { background: #9b6a3a; }
.ck-sq.can .ck-pc { box-shadow: 0 0 0 2px #ffc533aa, 0 3px 4px #0008; }
.ck-sq.must .ck-pc { animation: ck-must 1s ease-in-out infinite; }
.ck-sq.hint { box-shadow: inset 0 0 0 3px var(--gold); }
.ck-sq.hint::before { content: ''; position: absolute; inset: 4%; border-radius: 8px; box-shadow: 0 0 16px 4px #ffc533aa; animation: ck-pulse 1s ease-in-out 3; pointer-events: none; }
@keyframes ck-pulse { 0%, 100% { transform: scale(.85); opacity: .7; } 50% { transform: scale(1.1); opacity: 1; } }
@keyframes ck-must { 0%, 100% { transform: scale(1); } 50% { transform: scale(1.08); } }

.ck-pc { position: absolute; inset: 11%; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 15px; line-height: 1; }
.ck-pc.p0 { background: radial-gradient(circle at 35% 30%, #ff9a8a, #d63a2a 55%, #8e1d12); box-shadow: 0 3px 4px #0008, inset 0 -3px 0 #0004, inset 0 0 0 3px #ffffff22; }
.ck-pc.p1 { background: radial-gradient(circle at 35% 30%, #6f6a7d, #2a2633 55%, #121016); box-shadow: 0 3px 4px #0008, inset 0 -3px 0 #0006, inset 0 0 0 3px #ffffff18; }
.ck-pc.king::after { content: '👑'; font-size: 16px; filter: drop-shadow(0 1px 1px #0008); }
.ck-pc.crown { animation: ck-crown .6s ease; }
@keyframes ck-crown { 50% { transform: scale(1.3) rotate(10deg); } }
.ck-pc.gone { animation: ck-gone .35s ease forwards; }
@keyframes ck-gone { to { transform: scale(0); opacity: 0; } }
.ck-fly { position: absolute; z-index: 5; pointer-events: none; transition: transform .26s ease-in-out; }
.ck-board.busy .ck-sq { cursor: wait; }
.ck-tools { display: flex; gap: 10px; justify-content: center; margin-top: 12px; min-height: 40px; }