:root{--cream:#f7f4ed;--panel:#fff;--ink:#20242b;--muted:#667085;--line:#dedede;--gold:#f4ca3a;--green:#769656;--green-dark:#5f7f45;--light-square:#f0d9b5;--dark-square:#b58863;--danger:#b42318;--shadow:0 12px 30px #0000001c}*{box-sizing:border-box}body{background:var(--cream);color:var(--ink);margin:0;font-family:Arial,Helvetica,sans-serif}button,input,select{font:inherit}button{cursor:pointer;color:var(--ink);background:#fff;border:1px solid #c9c9c9;border-radius:10px;padding:10px 14px;font-weight:700}button:hover:not(:disabled){background:#f2f4f7}button:focus-visible,select:focus-visible,input:focus-visible{outline-offset:2px;outline:4px solid #175cd359}button:disabled{cursor:wait;opacity:.72}.appShell{max-width:1220px;margin:auto;padding:18px}.hero{color:#fff;box-shadow:var(--shadow);background:linear-gradient(135deg,#292929,#654b36);border-radius:22px;grid-template-columns:1.3fr .7fr;align-items:center;gap:22px;padding:30px;display:grid}.hero h1{margin:0 0 8px;font-size:clamp(34px,5vw,52px)}.hero p{color:#f7eadf}.eyebrow{text-transform:uppercase;letter-spacing:.12em;margin:0 0 8px;font-size:12px;font-weight:900}.primaryButton{background:var(--green);border-color:var(--green);color:#fff}.primaryButton:hover{background:var(--green-dark)!important}.heroCard{background:#ffffff1c;border:1px solid #ffffff47;border-radius:16px;gap:8px;padding:18px;display:grid}.mainNav{flex-wrap:wrap;gap:8px;margin:18px 0;display:flex}.mainNav button{border-radius:999px}.activeNav{color:#fff;background:#222;border-color:#222}.card,.trainerBoardPanel,.lessonPanel{background:var(--panel);border:1px solid var(--line);box-shadow:var(--shadow);border-radius:18px;padding:18px}.cardGrid{grid-template-columns:repeat(3,1fr);gap:16px;display:grid}.settingsGrid{grid-template-columns:1fr 1fr;gap:16px;display:grid}.muted{color:var(--muted)}.lessonChooser{margin-bottom:16px}.lessonButtons{grid-template-columns:repeat(5,minmax(130px,1fr));gap:8px;display:grid}.lessonButtons button{text-align:center;gap:4px;min-height:84px;display:grid}.lessonButtons button span:first-child{font-size:26px}.lessonButtons small{color:var(--muted)}.selectedLesson{border-color:var(--gold);box-shadow:0 0 0 3px #f4ca3a47}.comingSoonCard{text-align:center;padding:48px 20px}.largeIcon{font-size:56px}.trainerGrid{grid-template-columns:minmax(560px,1.2fr) minmax(300px,.8fr);align-items:start;gap:18px;display:grid}.lessonHeading{justify-content:space-between;align-items:flex-start;gap:16px;display:flex}.lessonHeading h2{margin:0}.engineSelector{gap:5px;min-width:175px;font-weight:800;display:grid}.engineSelector select{border:1px solid #bbb;border-radius:9px;padding:10px}.boardFrame{justify-content:center;gap:6px;margin:14px auto;display:flex}.chessBoard{background:#222;border:5px solid #282828;border-radius:8px;grid-template-rows:repeat(8,1fr);grid-template-columns:repeat(8,1fr);width:min(78vw,520px);height:min(78vw,520px);display:grid;overflow:hidden;box-shadow:0 10px 25px #0000003b}.boardSquare{border:0;border-radius:0;justify-content:center;align-items:center;min-width:0;padding:0;display:flex;position:relative}.lightSquare{background:var(--light-square)}.darkSquare{background:var(--dark-square)}.selectedSquare:after,.lastMoveSquare:after,.legalSquare:after{content:"";pointer-events:none;position:absolute;inset:0}.selectedSquare:after{background:#f7d7408c}.lastMoveSquare:after{background:#ffeb3b57}.legalSquare:before{content:"";z-index:2;background:#1919194d;border-radius:50%;width:20%;height:20%;position:absolute}.chessPiece{z-index:3;filter:drop-shadow(0 3px 2px #00000047);font-size:clamp(31px,7.1vw,58px);line-height:1;position:relative}.whitePiece{color:#f7f7f7;text-shadow:1px 1px #333,-1px -1px #333}.blackPiece{color:#222;text-shadow:1px 1px #eee}.rankLabels{grid-template-rows:repeat(8,1fr);width:22px;font-weight:900;display:grid}.rankLabels div,.fileLabels div{justify-content:center;align-items:center;display:flex}.fileLabels{grid-template-columns:repeat(8,1fr);width:min(78vw,520px);height:24px;font-weight:900;display:grid}.statusCard{background:#f7f7f7;border-radius:12px;flex-wrap:wrap;justify-content:center;gap:8px 18px;padding:12px;display:flex}.statusCard span{color:var(--muted)}.buttonRow{flex-wrap:wrap;justify-content:center;margin-top:10px;display:flex}.lessonPanel h3{margin-bottom:7px}.lessonPanel li{margin-bottom:8px;line-height:1.45}.goldButton{background:var(--gold);border-color:#d2aa17}.hintList p{border-left:4px solid var(--gold);background:#fff8d8;border-radius:8px;padding:10px}.toggleRow,.toggleCard{align-items:flex-start;gap:10px;display:flex}.toggleCard{border:1px solid var(--line);border-radius:12px;margin:10px 0;padding:13px}.toggleCard small{color:var(--muted);margin-top:4px;line-height:1.35;display:block}.engineNote{color:#344054;background:#eef4ff;border-radius:10px;margin-top:20px;padding:10px}footer{text-align:center;color:var(--muted);margin:26px 0 10px;font-size:13px}.dyslexiaMode{letter-spacing:.025em;font-family:Verdana,Tahoma,Arial,sans-serif;line-height:1.62}.largeText{font-size:118%}.highContrast{--cream:#fff;--panel:#fff;--ink:#000;--muted:#222;--line:#000;--light-square:#fff0a8;--dark-square:#4f331f}.reducedMotion *{transition:none!important;animation:none!important}@media (width<=1000px){.trainerGrid{grid-template-columns:1fr}.lessonButtons{grid-template-columns:repeat(3,1fr)}}@media (width<=760px){.appShell{padding:10px}.hero,.cardGrid,.settingsGrid{grid-template-columns:1fr}.lessonButtons{grid-template-columns:1fr 1fr}.lessonHeading{display:grid}.engineSelector{width:100%}.chessBoard,.fileLabels{width:min(88vw,520px)}.chessBoard{height:min(88vw,520px)}}@media (width<=460px){.lessonButtons{grid-template-columns:1fr}.hero{padding:22px}}.movementLine:after{content:"";pointer-events:none;z-index:1;background:#4a90e23d;position:absolute;inset:0}.coachCard{border-left:5px solid var(--green);background:#eef7e8;border-radius:12px;margin-top:12px;padding:13px 15px}.coachCard p{margin:5px 0 0;line-height:1.45}