:root{--bg: #0d1117;--surface: #161b22;--border: #30363d;--text: #c9d1d9;--text-muted: #8b949e;--accent: #58a6ff;--accent-hover: #79c0ff;--light-square: #d4a574;--dark-square: #8b5a3c;--selected: #b8956a;--success: #3fb950}*{margin:0;padding:0;box-sizing:border-box}html,body,#root{height:100%;overflow:auto}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,sans-serif;background:var(--bg);color:var(--text);-webkit-font-smoothing:antialiased}.app{min-height:100vh;display:flex;flex-direction:column}.header{padding:1.5rem 2rem;background:var(--surface);border-bottom:1px solid var(--border);display:flex;justify-content:space-between;align-items:center;gap:2rem;flex-wrap:wrap;min-height:60px}.logo-title{display:flex;align-items:center;gap:.75rem;flex-wrap:wrap}.chess-logo{font-size:2rem;color:var(--accent);filter:drop-shadow(0 2px 4px rgba(0,0,0,.3))}.title-section h1{font-size:1.5rem;font-weight:600;margin:0;color:var(--text)}.title-section .subtitle{font-size:.75rem;color:var(--text-muted);margin-left:.5rem;padding:.25rem .75rem;background:var(--surface);border:1px solid var(--border);border-radius:12px}.controls{display:flex;gap:2rem;align-items:center;flex-wrap:wrap}.control-group label{display:block;font-size:.75rem;font-weight:500;color:var(--text-muted);margin-bottom:.5rem;text-transform:uppercase;letter-spacing:.5px}.button-row{display:flex;gap:.5rem}button{padding:.5rem 1rem;border:1px solid var(--border);border-radius:6px;background:transparent;color:var(--text);cursor:pointer;font-size:.875rem;font-weight:500;transition:all .15s 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ease}.position-input:focus{outline:none;border-color:var(--accent);background:var(--surface)}.position-input::placeholder{color:var(--text-muted);opacity:.6}.position-input::-webkit-inner-spin-button,.position-input::-webkit-outer-spin-button{-webkit-appearance:none;margin:0}.position-input[type=number]{-moz-appearance:textfield;appearance:textfield}.game-area{flex:1;display:grid;grid-template-columns:1fr auto;gap:2rem;padding:2rem;overflow:auto;align-items:start;max-width:100%}.board-section{display:flex;justify-content:center;align-items:center;min-height:0;width:100%}.board-wrapper{background:var(--surface);padding:1.5rem;border-radius:8px;border:1px solid var(--border);box-shadow:0 4px 12px #0000004d}.chessboard{display:grid;grid-template-columns:repeat(8,minmax(60px,80px));grid-template-rows:repeat(8,minmax(60px,80px));gap:0;border:2px solid #1f2329;border-radius:2px;box-shadow:0 2px 8px #0006;margin:0 auto;max-width:640px;max-height:640px}.square{aspect-ratio:1;display:flex;align-items:center;justify-content:center;cursor:pointer;position:relative;-webkit-user-select:none;user-select:none;transition:filter .1s;overflow:visible}.square:hover{filter:brightness(1.1)}.square.light{background:var(--light-square)}.square.dark{background:var(--dark-square)}.square.selected{background:var(--selected)!important;box-shadow:inset 0 0 0 3px #646f40cc}.piece{font-size:clamp(3rem,7vw,4rem);line-height:1;z-index:5;pointer-events:none}.piece.white{color:wheat;filter:drop-shadow(0 2px 3px rgba(0,0,0,.6))}.piece.black{color:#2c1810;filter:drop-shadow(0 1px 2px rgba(255,255,255,.15))}.move-dot{width:25%;height:25%;background:#14551e66;border-radius:50%;pointer-events:none;position:absolute}.move-ring{width:85%;height:85%;border:3px solid rgba(20,85,30,.5);border-radius:50%;pointer-events:none;position:absolute}.move-ring{width:90%;height:90%;border:3px solid rgba(20,85,30,.5);border-radius:50%;pointer-events:none}.sidebar{width:320px;display:flex;flex-direction:column;gap:1rem;max-height:100%;overflow-y:auto}.sidebar::-webkit-scrollbar{width:6px}.sidebar::-webkit-scrollbar-track{background:transparent}.sidebar::-webkit-scrollbar-thumb{background:var(--border);border-radius:3px}.sidebar::-webkit-scrollbar-thumb:hover{background:var(--text-muted)}.card{background:var(--surface);border:1px solid var(--border);border-radius:8px;overflow:hidden}.card.game-over{border-color:var(--accent)}.card.game-over .card-header h3{color:var(--accent)}.card-header{padding:1rem 0 1rem 1.25rem;border-bottom:1px solid var(--border);display:flex;justify-content:space-between;align-items:center;gap:0}.card-header h3{margin:0;font-size:.875rem;font-weight:600;color:var(--text);text-transform:uppercase;letter-spacing:.5px;flex:0 1 auto;white-space:nowrap}.copy-btn{padding:.375rem .5rem;font-size:1.1rem;width:auto;height:1.75rem;display:flex;align-items:center;justify-content:center;border:none;background:transparent;color:var(--text-muted);cursor:pointer;border-radius:4px;transition:all .15s;flex-shrink:0;margin-left:auto}.copy-btn:hover{background:var(--bg);color:var(--accent)}.copy-btn svg{width:16px;height:16px}.card-body{padding:1.25rem}.status-item{display:flex;justify-content:space-between;align-items:center;padding:.75rem 0;border-bottom:1px solid var(--border)}.status-item:last-child{border-bottom:none}.status-label{font-size:.8rem;color:var(--text-muted);font-weight:500}.status-value{font-size:.875rem;color:var(--text);font-weight:500}.moves-list{font-family:Consolas,Monaco,Courier New,monospace;font-size:.8rem;color:var(--text-muted);line-height:1.6;max-height:200px;overflow-y:auto;word-wrap:break-word;overflow-wrap:break-word}.moves-list::-webkit-scrollbar{width:6px}.moves-list::-webkit-scrollbar-track{background:transparent}.moves-list::-webkit-scrollbar-thumb{background:var(--border);border-radius:3px}.moves-list::-webkit-scrollbar-thumb:hover{background:var(--text-muted)}.fen-display{font-family:Consolas,Monaco,Courier New,monospace;font-size:.75rem;color:var(--text-muted);line-height:1.5;word-break:break-all;background:var(--bg);padding:.75rem;border-radius:4px;border:1px solid var(--border)}.promotion-overlay{position:fixed;inset:0;background:#000000bf;display:flex;align-items:center;justify-content:center;z-index:1000;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.promotion-dialog{background:var(--surface);border:2px solid var(--accent);border-radius:12px;padding:2rem;box-shadow:0 10px 40px #00000080;animation:slideIn .2s ease-out;max-width:min(450px,calc(100vw - 2rem));width:100%}@keyframes slideIn{0%{transform:translateY(-20px);opacity:0}to{transform:translateY(0);opacity:1}}.promotion-dialog h3{margin:0 0 1.5rem;color:var(--accent);text-align:center;font-size:1.25rem}.promotion-options{display:flex;gap:1rem;justify-content:center;flex-wrap:wrap}.promotion-piece{width:80px;height:80px;font-size:3.5rem;background:var(--light-square);border:2px solid var(--border);border-radius:8px;cursor:pointer;transition:all .2s ease;display:flex;align-items:center;justify-content:center}.promotion-piece:hover{background:var(--dark-square);border-color:var(--accent);transform:scale(1.1)}.promotion-piece:active{transform:scale(.95)}@media(max-width:1200px){.game-area{grid-template-columns:1fr;justify-items:center;gap:1.5rem;padding:1.5rem}.sidebar{width:100%;max-width:600px}}@media(max-width:768px){.header{padding:1rem;flex-direction:column;align-items:stretch;gap:1rem}.title-section h1{font-size:1.25rem}.chess-logo{font-size:1.75rem}.title-section .subtitle{font-size:.7rem;padding:.2rem .65rem}.controls{flex-direction:column;gap:1rem}.control-group{width:100%}.control-group label{text-align:center}.button-row{justify-content:center;flex-wrap:wrap}button{flex:1;min-width:100px}.game-area{padding:1rem;gap:1rem}.board-section{width:100%;padding:0}.board-wrapper{padding:.5rem;margin:0 auto;max-width:100%}.chessboard{grid-template-columns:repeat(8,calc((100vw - 3rem)/8));grid-template-rows:repeat(8,calc((100vw - 3rem)/8));max-width:500px;max-height:500px}.piece{font-size:clamp(2.5rem,8vw,3.5rem)}.sidebar{max-width:100%}.card{position:relative}.card-header{flex-direction:column;align-items:flex-start;gap:.5rem;padding-right:3rem}.copy-btn{position:absolute;top:.5rem;right:-1.5rem}.card-body{padding:1rem}}@media(max-width:480px){.header{padding:.75rem}.title-section h1{font-size:1.1rem}.chess-logo{font-size:1.5rem}.title-section .subtitle{font-size:.65rem;margin-left:.25rem;padding:.2rem .6rem}.control-group label{font-size:.7rem}button{padding:.5rem .75rem;font-size:.8rem}.game-area{padding:.5rem}.board-wrapper{padding:.4rem}.chessboard{grid-template-columns:repeat(8,calc((100vw - 2rem)/8));grid-template-rows:repeat(8,calc((100vw - 2rem)/8))}.piece{font-size:clamp(2rem,7vw,3rem)}.card-header{padding:.75rem 1rem}.card-header h3{font-size:.8rem}.card-body{padding:.75rem}.status-item{padding:.5rem 0}.status-label,.status-value{font-size:.75rem}.moves-list,.fen-display{font-size:.7rem}.promotion-dialog{padding:1.25rem;border-radius:8px}.promotion-dialog h3{font-size:1rem;margin-bottom:1rem}.promotion-options{gap:.75rem}.promotion-piece{width:65px;height:65px;font-size:2.75rem}}@media(max-width:360px){.game-area{padding:.4rem}.board-wrapper{padding:.25rem}.chessboard{grid-template-columns:repeat(8,calc((100vw - 1.5rem)/8));grid-template-rows:repeat(8,calc((100vw - 1.5rem)/8))}.piece{font-size:clamp(1.75rem,6.5vw,2.5rem)}.promotion-dialog{padding:1rem;border-radius:6px}.promotion-dialog h3{font-size:.9rem;margin-bottom:.75rem}.promotion-options{gap:.5rem}.promotion-piece{width:55px;height:55px;font-size:2.25rem;border-radius:6px}}