:root{--icon-new-game:"fa-plus-circle";--icon-reset-game:"fa-refresh";--icon-undo-move:"fa-undo";--icon-redo-move:"fa-redo";--icon-resign-game:"fa-flag";--icon-rotate-left:"fa-arrow-left";--icon-rotate-right:"fa-arrow-right";--icon-toggle-audio:"fa-volume-up";--icon-start-welcome:"fa-play";--icon-start-game:"fa-play";--icon-cancel-game:"fa-times";--icon-ai-spinner:"fa-atom";--light-square:#f0d9b5;--dark-square:#b58863;--highlight-square:#ffff0080;--available-move:#00ff004d;--capture-move:#f006;--customization-target:#f39c1280;--customization-active:#f39c12}*{box-sizing:border-box;margin:0;padding:0}body{color:#fff;background:radial-gradient(#1a1a1a 0%,#000 100%) 50%/100% 100% no-repeat,linear-gradient(45deg,#c0c0c01a 0%,#ff00000d 25%,#c0c0c01a 50%,#ff00000d 75%,#c0c0c01a 100%) 0 0/200px 200px,linear-gradient(-45deg,#ffffff0d 0%,#8b00001a 50%,#ffffff0d 100%) 0 0/150px 150px;width:100vw;height:100vh;font-family:Vanadium Sans Semi-Extended,sans-serif;overflow:hidden}.app-container{flex-direction:column;justify-content:center;align-items:center;width:100vw;height:100vh;display:flex}.board-container{width:min(90vh,90vw);height:min(90vh,90vw);margin:20px;position:relative}.chess-board{border:2px solid #34495e;border-radius:10px;grid-template-rows:repeat(10,1fr);grid-template-columns:repeat(10,1fr);gap:0;width:100%;height:100%;display:grid;position:relative;overflow:hidden}.cell{cursor:pointer;-webkit-user-select:none;user-select:none;justify-content:center;align-items:center;font-size:3rem;display:flex;position:relative}.cell.light-square{background-color:var(--light-square)}.cell.dark-square{background-color:var(--dark-square)}.chess-piece{cursor:grab;z-index:10;font-size:3rem;transition:transform .2s}.chess-piece.white{color:#fff;text-shadow:1px 1px 2px #00000080}.chess-piece.black{color:#333;text-shadow:1px 1px 2px #ffffff80}.chess-piece:hover{z-index:20;transform:scale(1.1)}.chess-piece.last-moved{filter:drop-shadow(0 0 5px #ff0)}.tooltip{visibility:hidden;color:#fff;pointer-events:none;white-space:nowrap;z-index:10000;filter:drop-shadow(0 1px #ffffff1a)drop-shadow(0 -1px #ffffff1a)drop-shadow(1px 0 #ffffff1a)drop-shadow(-1px 0 #ffffff1a)drop-shadow(1px 1px #ffffff1a)drop-shadow(-1px -1px #ffffff1a)drop-shadow(1px -1px #ffffff1a)drop-shadow(-1px 1px #ffffff1a);opacity:0;transition:opacity .4 ease-in-out, visibility 0s linear .4s;background:#555;border:3px solid #333;border-radius:20px;padding:8px 12px;font-size:14px;display:block;position:absolute;transform:translateY(-3px);box-shadow:0 4px 12px #0000004d}.tooltip.show{visibility:visible;opacity:1;transition:opacity .4s ease-in-out;transform:translateY(0)}.tooltip-arrow{width:0;height:0;position:absolute;bottom:-1px;left:50%;transform:translate(-50%)}.tooltip-arrow:before{content:"";border:14px solid #0000;border-top-color:#333;position:absolute;top:0;left:50%;transform:translate(-50%)}.tooltip-arrow:after{content:"";border:13px solid #0000;border-top-color:#555;position:absolute;top:-3px;left:50%;transform:translate(-50%)}.highlight{pointer-events:none;border-radius:50%;width:100%;height:100%;position:absolute}.available-move{background-color:var(--available-move)}.capture-move{background-color:var(--capture-move)}.selected-piece{background-color:var(--highlight-square)}.game-controls{background-color:#34495e;border-radius:10px;flex-wrap:wrap;justify-content:center;align-items:center;gap:8px;width:min(90vh,90vw);margin:20px;padding:8px;display:flex}.customization-active{color:var(--customization-active)!important}.customization-target{background-color:var(--customization-target)!important}.piece-selection-modal{z-index:1001;color:#333;background-color:#fffffff2;border:2px solid #34495e;border-radius:10px;max-width:400px;padding:15px;position:absolute;box-shadow:0 4px 20px #0000004d}.piece-selection-modal h3{color:#34495e;text-align:center;margin-top:0;margin-bottom:15px;font-size:1.2rem}.piece-options{grid-template-columns:repeat(6,1fr);gap:8px;margin-bottom:10px;display:grid}.piece-option{cursor:pointer;background:0 0;border:2px solid #34495e;border-radius:6px;justify-content:center;align-items:center;width:40px;height:40px;padding:0;font-size:1.5rem;transition:all .2s;display:flex}.piece-option:hover{background-color:#34495e;transform:scale(1.1)}.piece-option i{font-size:1.5rem}.ai-spinner{opacity:.3;justify-content:center;align-items:center;width:40px;height:40px;transition:opacity .3s;display:flex}#whiteSpinner{width:80px;margin-left:-20px}#blackSpinner{width:80px;margin-right:-20px}.ai-spinner.active{opacity:1}.ai-spinner.white-thinking{color:#fff;filter:drop-shadow(1px 1px #00000080)drop-shadow(-1px -1px #00000080)drop-shadow(1px -1px #00000080)drop-shadow(-1px 1px #00000080)}.ai-spinner.black-thinking{color:#000;filter:drop-shadow(1px 1px #ffffff1a)drop-shadow(-1px -1px #ffffff1a)drop-shadow(1px -1px #ffffff1a)drop-shadow(-1px 1px #ffffff1a)}.ai-spinner svg,.ai-spinner i{font-size:2.875rem}button{color:inherit;cursor:pointer;opacity:.7;background:0 0;border:none;justify-content:center;align-items:center;width:40px;height:40px;padding:0;transition:opacity .3s;display:flex}button svg,button i{font-size:1.875rem}button:hover:not(:disabled){opacity:1}button:disabled{cursor:not-allowed;opacity:.5}.game-status{text-align:center;flex:1;padding:0 20px;font-size:1.2rem;font-weight:700}.coordinate-labels{color:#888;pointer-events:none;-webkit-user-select:none;user-select:none;z-index:100;font-size:.8rem;font-weight:700;position:absolute}.file-labels{justify-content:space-between;width:100%;display:flex}.file-labels.top{top:-25px;left:0}.file-labels.bottom{margin-top:5px}.file-label{text-align:center;width:10%}.rank-labels{flex-direction:column;justify-content:space-between;height:100%;display:flex}.rank-labels.left{position:absolute;top:0;left:-25px}.rank-labels.right{position:absolute;top:0;right:-25px}.rank-label{justify-content:center;align-items:center;width:20px;height:10%;display:flex}.modal{z-index:1000;background-color:#000000b3;justify-content:center;align-items:center;width:100%;height:100%;display:none;position:fixed;top:0;left:0}.modal-content{color:#333;background-color:#fefefe;border-radius:10px;width:300px;max-width:80%;padding:20px}.welcome-content{background:linear-gradient(135deg, var(--light-square) 0%, var(--dark-square) 100%);color:#333;border:3px solid #8b4513;border-radius:15px;width:90%;max-width:800px;max-height:90vh;overflow-y:auto;box-shadow:0 10px 30px #0000004d}.welcome-header{text-align:center;margin-bottom:20px}.welcome-title{color:#2c1810;text-shadow:2px 2px 4px #0000004d;margin-bottom:10px;font-size:3rem;font-weight:700}.welcome-subtitle{color:#5d4037;font-size:1.2rem;font-style:italic}.welcome-description{text-align:center;color:#3e2723;margin-bottom:30px;font-size:1.1rem;line-height:1.6}.welcome-features h2{text-align:center;color:#2c1810;margin-bottom:20px;font-size:1.8rem}.features-grid{grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:20px;margin-bottom:30px;display:grid}.feature-item{text-align:center;background:#ffffffe6;border-radius:10px;padding:20px;transition:transform .3s;box-shadow:0 4px 8px #0000001a}.feature-item:hover{transform:translateY(-5px)}.feature-item>i,.feature-item>svg,.feature-icon{color:var(--dark-square);margin-bottom:10px;font-size:2.5rem}.feature-item h3{color:#2c1810;margin-bottom:10px;font-size:1.2rem}.feature-item p{color:#5d4037;font-size:.9rem;line-height:1.4}.welcome-actions{text-align:center;justify-content:center;display:flex}.start-game-btn{color:#fff;cursor:pointer;white-space:nowrap;background:linear-gradient(135deg,#27ae60 0%,#2ecc71 100%);border:none;border-radius:25px;width:auto;padding:25px 40px;font-size:1.8rem;font-weight:700;transition:all .3s;box-shadow:0 4px 15px #27ae604d}.start-game-btn:hover{background:linear-gradient(135deg,#229954 0%,#27ae60 100%);transform:scale(1.05);box-shadow:0 6px 20px #27ae6066}.modal-content h2{color:#34495e;margin-bottom:20px}.setup-option{margin-bottom:15px}.setup-option label{margin-bottom:5px;font-weight:700;display:block}.setup-option select{border:1px solid #ddd;border-radius:4px;width:100%;margin-bottom:5px;padding:8px}.setup-option p{color:#666;margin-top:5px;font-size:.8rem;font-style:italic}.modal-buttons{justify-content:space-between;margin-top:20px;display:flex}.modal-buttons button{color:#fff;cursor:pointer;background-color:#3498db;border:none;border-radius:5px;width:48%;padding:10px 20px;font-size:1rem}.modal-buttons button:hover{background-color:#2980b9}.modal-buttons button#cancelGame{background-color:#e74c3c}.modal-buttons button#cancelGame:hover{background-color:#c0392b}.promotion-content{text-align:center;color:#fff;background-color:#34495e;max-width:800px}.promotion-content h2{color:#fff;margin-bottom:20px}.promotion-options{flex-wrap:wrap;justify-content:center;gap:10px;display:flex}.promotion-piece.no-border{background:0 0;border:none}.promotion-piece.function-btn{color:#fff;background-color:#ffffff1a;border:2px solid #34495e;min-width:60px;height:60px;padding:0;font-size:1rem}.promotion-piece.function-btn:hover{background-color:#fff3}.promotion-piece.function-btn i{font-size:2rem}.customization-content{text-align:center;color:#fff;background-color:#34495e;width:100%;max-width:525px;max-height:250px;padding:20px}.customization-options{flex-direction:column;gap:0;display:flex}.function-buttons{justify-content:center;gap:10px;margin-bottom:20px;display:flex}.customization-btn{cursor:pointer;color:#fff;background:#ffffff1a;border:2px solid #34495e;border-radius:8px;justify-content:center;align-items:center;width:60px;height:60px;font-size:1rem;transition:all .3s;display:flex}.customization-btn:hover{background-color:#fff3;transform:scale(1.1)}.customization-btn i{font-size:2rem}.piece-row{flex-wrap:wrap;justify-content:center;gap:10px;margin-bottom:15px;display:flex}.piece-btn{cursor:pointer;background:0 0;border:none;justify-content:center;align-items:center;width:60px;height:60px;padding:0;display:flex}.piece-btn:hover{transform:scale(1.1)}.fa-rotate-90{transform:rotate(90deg)}.promotion-piece{cursor:pointer;color:#34495e;background:0 0;border:2px solid #34495e;border-radius:8px;justify-content:center;align-items:center;min-width:60px;height:60px;padding:0 8px;font-size:1rem;transition:all .3s;display:flex}.promotion-piece:hover{color:#fff;background-color:#34495e;transform:scale(1.1)}.move-history{color:#333;background-color:#ffffffe6;border:1px solid #ddd;border-radius:5px;width:200px;max-height:80vh;padding:10px;position:absolute;top:10px;right:10px;overflow-y:auto}.move-history h3{color:#34495e;border-bottom:1px solid #eee;margin-top:0;margin-bottom:10px;padding-bottom:5px;font-size:1rem}.move-list{font-family:monospace;font-size:.9rem;line-height:1.4}.move-item{margin-bottom:5px;padding:2px 0}.move-item.white{color:#555}.move-item.black{color:#333;font-weight:700}.move-number{color:#666;width:20px;display:inline-block}.move-notation{margin-left:10px}.move-notation.white{color:#555}.move-notation.black{color:#333}.orientation-button{opacity:.7;justify-content:center;align-items:center;width:40px;height:40px;transition:opacity .3s;display:flex}.orientation-button:hover{opacity:1}.orientation-button svg,.orientation-button i{font-size:1.875rem}@media (width<=768px){.chess-piece{font-size:2rem}.game-controls{flex-direction:column;gap:10px}.welcome-title{font-size:2rem}.welcome-subtitle,.welcome-description{font-size:1rem}.features-grid{grid-template-columns:1fr;gap:15px}.feature-item{padding:15px}.feature-icon{font-size:2rem}.start-game-btn{padding:12px 30px;font-size:1rem}}