.tic-tac-toe-board-container{display:flex;justify-content:center;margin:20px 0;perspective:1000px}.tic-tac-toe-board{display:grid;grid-template-columns:repeat(3,1fr);grid-template-rows:repeat(3,1fr);gap:8px;width:300px;height:300px;background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);border:4px solid #5a67d8;border-radius:20px;padding:15px;box-shadow:0 8px 25px #0000004d inset 0 1px 0 #fff3;margin:0 auto;animation:boardSlideIn .5s ease-out}@keyframes boardSlideIn{from{opacity:0;transform:translateY(-30px) scale(0.9)}to{opacity:1;transform:translateY(0) scale(1)}}.tic-tac-toe-cell{background:linear-gradient(145deg,#fff,#f0f4f8);border:3px solid transparent;border-radius:15px;display:flex;align-items:center;justify-content:center;cursor:pointer;transition:all .3s cubic-bezier(0.175,0.885,0.32,1.275);position:relative;overflow:hidden;font-size:3rem;font-weight:700;box-shadow:0 4px 15px #0000001a inset 0 1px 0 #fffc}.tic-tac-toe-cell:hover{background:linear-gradient(145deg,#e2e8f0,#cbd5e0);transform:scale(1.05) translateY(-2px);box-shadow:0 8px 25px #0003 inset 0 1px 0 #ffffffe6;border-color:#667eea4d}.tic-tac-toe-cell:active{transform:scale(0.95);transition:transform .1s ease}.tic-tac-toe-cell.player-symbol{color:#48bb78;background:linear-gradient(145deg,#f0fff4,#c6f6d5);border-color:#48bb78;animation:symbolAppear .4s ease-out;text-shadow:0 2px 4px #48bb784d 0 0 20px #48bb7833}.tic-tac-toe-cell.cpu-symbol{color:#f56565;background:linear-gradient(145deg,#fff5f5,#fed7d7);border-color:#f56565;animation:symbolAppear .4s ease-out;text-shadow:0 2px 4px #f565654d 0 0 20px #f5656533}@keyframes symbolAppear{0%{opacity:0;transform:scale(0) rotate(180deg)}50%{opacity:.8;transform:scale(1.2) rotate(90deg)}100%{opacity:1;transform:scale(1) rotate(0deg)}}.tic-tac-toe-cell.winning-cell{background:linear-gradient(145deg,#ffeaa7,#fdcb6e);border-color:#e17055;animation:victoryPulse 1s ease-in-out infinite;box-shadow:0 0 30px #fdcb6e99 0 8px 25px #0003}@keyframes victoryPulse{0%,100%{transform:scale(1);box-shadow:0 0 30px #fdcb6e99 0 8px 25px #0003}50%{transform:scale(1.03);box-shadow:0 0 40px #fdcb6ecc 0 12px 35px #0000004d}}.score-display{padding:15px;border-radius:15px;transition:all .3s ease}.score-display.player-score{background:linear-gradient(135deg,#c6f6d5,#9ae6b4);border:2px solid #48bb78}.score-display.cpu-score{background:linear-gradient(135deg,#fed7d7,#fbb6ce);border:2px solid #f56565}.score-symbol{font-size:2.5rem;font-weight:700;margin-bottom:8px}.score-label{font-size:.9rem;font-weight:600;opacity:.8}.statistic-item{padding:10px;transition:transform .2s ease}.statistic-item:hover{transform:translateY(-2px)}.statistic-number{font-size:1.8rem;font-weight:700;margin-bottom:5px}.statistic-label{font-size:.8rem;font-weight:500;opacity:.7}.difficulty-card,.turn-card{cursor:pointer;transition:all .3s cubic-bezier(0.175,0.885,0.32,1.275);border:2px solid #e2e8f0;position:relative;overflow:hidden}.difficulty-card::before,.turn-card::before{content:'';position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,#fff6,transparent);transition:left .5s ease}.difficulty-card:hover,.turn-card:hover{border-color:#667eea;transform:translateY(-2px) scale(1.02);box-shadow:0 4px 15px #0000001a}.difficulty-card:hover::before,.turn-card:hover::before{left:100%}.difficulty-card.selected,.turn-card.selected{border-color:#667eea;background:linear-gradient(145deg,#edf2f7,#e2e8f0);box-shadow:0 4px 15px #667eea33;transform:translateY(-1px)}.difficulty-card:active,.turn-card:active{transform:scale(0.98)}.game-end-icon{font-size:4rem;animation:iconCelebration 1s ease-in-out}@keyframes iconCelebration{0%,100%{transform:scale(1) rotateZ(0deg)}25%{transform:scale(1.2) rotateZ(-5deg)}50%{transform:scale(1.3) rotateZ(5deg)}75%{transform:scale(1.1) rotateZ(-3deg)}}.game-end-message{font-size:1.5rem;font-weight:700;margin-bottom:15px}.game-end-stats{background:linear-gradient(145deg,#f7fafc,#edf2f7);border-radius:12px;padding:15px;margin-top:15px}#currentTurn{animation:turnPulse 2s ease-in-out infinite;font-weight:600;text-shadow:0 1px 2px #0000001a}@keyframes turnPulse{0%,100%{opacity:1}50%{opacity:.7}}@media (max-width: 576px){.tic-tac-toe-board{width:250px;height:250px;gap:6px;padding:10px}.tic-tac-toe-cell{font-size:2.5rem;border-radius:10px}.score-symbol{font-size:2rem}.difficulty-option{padding:15px}.difficulty-icon{font-size:2rem}}@media (max-width: 480px){.tic-tac-toe-board{width:220px;height:220px}.tic-tac-toe-cell{font-size:2rem}}@media (prefers-reduced-motion: reduce){.tic-tac-toe-cell,.difficulty-option,.score-display,.statistic-item{animation:none;transition:none}.tic-tac-toe-cell:hover,.difficulty-option:hover{transform:none}}@media (prefers-color-scheme: dark){.tic-tac-toe-board{background:linear-gradient(135deg,#4a5568 0%,#2d3748 100%);border-color:#4a5568}.tic-tac-toe-cell{background:linear-gradient(145deg,#2d3748,#1a202c);color:#f7fafc}.tic-tac-toe-cell:hover{background:linear-gradient(145deg,#4a5568,#2d3748)}}.accordion-body::-webkit-scrollbar{width:6px}.accordion-body::-webkit-scrollbar-track{background:#f1f1f1;border-radius:3px}.accordion-body::-webkit-scrollbar-thumb{background:linear-gradient(135deg,#667eea,#764ba2);border-radius:3px}.accordion-body::-webkit-scrollbar-thumb:hover{background:linear-gradient(135deg,#5a67d8,#6b46c1)}