:root{--felt:#0b5d2a;--felt-dark:#062716;--felt-light:#11733a;--ivory:#f6f3e7;--gold:#c7aa63}html,body,#root{height:100%}body{margin:0;font-family:Arial,Helvetica,sans-serif;color:var(--ivory);background:linear-gradient(180deg,rgba(0,0,0,.5),transparent 30%),radial-gradient(1400px 700px at 30% 10%,rgba(255,255,255,.06),transparent 60%),radial-gradient(900px 450px at 85% 80%,rgba(0,0,0,.35),transparent 60%),linear-gradient(180deg,var(--felt-dark),#04160c);background-color:var(--felt-dark)}.app-center{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px}.game-shell{width:min(920px,92vw);background:linear-gradient(180deg,#ffffff0d,#0000001a);border:1px solid rgba(255,255,255,.15);border-radius:18px;box-shadow:0 30px 60px #00000059,inset 0 0 80px #00000040;-webkit-backdrop-filter:blur(2px);backdrop-filter:blur(2px);padding:24px 28px}.game-header{display:flex;align-items:center;gap:12px;margin-bottom:10px;flex-wrap:wrap}.game-title{margin:0;letter-spacing:.5px;font-size:clamp(22px,3vw,36px)}.set-select{background:#00000040;color:var(--ivory);border:1px solid rgba(255,255,255,.2);border-radius:10px;padding:6px 10px}.score-wrap{margin-left:auto;display:flex;align-items:center;gap:16px;white-space:nowrap}.moves-line{opacity:.9;margin:6px 0 12px}.chessboard-housing{padding:10px;background:linear-gradient(180deg,#f6f3e7,#e7ddb9);border-radius:14px;border:2px solid var(--gold);box-shadow:inset 0 2px #ffffffb3,0 12px 30px #00000073}.board-row{display:flex;gap:24px;align-items:flex-start;flex-wrap:wrap}.choices{display:grid;grid-template-columns:repeat(2,minmax(180px,1fr));gap:12px}.btn{font:inherit;color:var(--ivory);padding:10px 14px;border-radius:10px;border:1px solid rgba(255,255,255,.2);background:#00000040;cursor:pointer;transition:transform .08s ease,background .15s ease,box-shadow .15s ease}.btn:hover{transform:translateY(-1px);background:#ffffff14;box-shadow:0 6px 16px #00000040}.btn:disabled{opacity:.6;cursor:not-allowed}.btn-primary{background:linear-gradient(180deg,#24c07b,#118a56);border-color:#0003}.btn-primary:hover{background:linear-gradient(180deg,#2fd190,#149261)}.result{margin-left:12px;font-weight:800}.result.ok{color:#90f0b6}.result.bad{color:#ff97a3}.btn-wrong{color:#ff97a3;background:#ff000024;border-color:#ff000059}.btn-wrong:hover{transform:none;background:#f003;box-shadow:none}.desc-box{margin-top:8px;padding:10px 12px;background:#00000040;border:1px solid rgba(255,255,255,.18);border-radius:10px;max-width:420px;line-height:1.35}.side-col{min-width:320px;flex:1;display:flex;flex-direction:column;gap:14px}