:root{--bg:#f5f4f1;--surface:#fff;--surface-2:#f8f7f5;--text:#1c1b19;--muted:#6e6a63;--border:#e4e1db;--accent:#3b7a57;--accent-hover:#336b4c;--accent-soft:#3b7a571f;--accent-text:#fff;--focus:#3b7a5773;--sq-light:#f0d9b5;--sq-dark:#b58863;--sq-highlight:#9bc7006b;--sq-selected:#14551e80;--correct:#2f8a4c;--correct-bg:#eaf5ee;--wrong:#c4493a;--wrong-bg:#fbeeec;--flame:#e8590c;--radius:12px;--shadow-board:0 1px 2px #00000014, 0 10px 30px #0000001f;--shadow-card:0 1px 2px #0000000a;--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light}@media (prefers-color-scheme:dark){:root{--bg:#161512;--surface:#23211e;--surface-2:#2a2825;--text:#e8e6e1;--muted:#9b968d;--border:#3a3733;--accent:#5aa478;--accent-hover:#6bb488;--accent-soft:#5aa47829;--accent-text:#0f1a13;--focus:#5aa47880;--correct:#63b67f;--correct-bg:#63b67f1f;--wrong:#e0705f;--wrong-bg:#e0705f1f;--flame:#ff8a3d;--shadow-board:0 1px 2px #0006, 0 10px 30px #00000073;--shadow-card:none;--lightningcss-light: 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ring-glow{0%{filter:drop-shadow(0 0 #0000)}30%{filter:drop-shadow(0 0 6px var(--correct))}to{filter:drop-shadow(0 0 #0000)}}.pop{animation:.35s cubic-bezier(.3,1.6,.5,1) pop;display:inline-block}@keyframes pop{0%{transform:scale(1)}40%{color:var(--accent);transform:scale(1.35)}to{transform:scale(1)}}.celebrate{border-radius:6px;animation:1.2s ease-out flash}@keyframes flash{0%,30%{color:var(--accent);text-shadow:0 0 12px var(--accent-soft)}}.toasts{z-index:20;pointer-events:none;flex-direction:column;gap:8px;width:min(340px,100vw - 32px);display:flex;position:fixed;bottom:16px;right:16px}.toast{border:1px solid var(--border);border-left:4px solid var(--accent);background:var(--surface);pointer-events:auto;border-radius:10px;align-items:flex-start;gap:10px;padding:12px 10px 12px 14px;animation:.25s ease-out toast-in;display:flex;box-shadow:0 4px 12px #00000014,0 12px 32px #00000024}@keyframes toast-in{0%{opacity:0;transform:translateY(8px)}}.toast__text{flex-direction:column;flex:1;font-size:.875rem;display:flex}.toast__text span{color:var(--muted)}.toast__close{color:var(--muted);background:0 0;border:none;padding:0 4px;font-size:1.2rem;line-height:1}.progress-dialog{border:1px solid var(--border);background:var(--surface);width:min(640px,100vw - 32px);max-height:calc(100dvh - 48px);color:var(--text);border-radius:16px;padding:0;box-shadow:0 24px 64px #00000040}.progress-dialog[open]{animation:.18s ease-out dialog-in}@keyframes dialog-in{0%{opacity:0;transform:translateY(8px)scale(.98)}}.progress-dialog::backdrop{background:#14120f73}.progress{padding:4px 22px 22px}.progress__header{z-index:1;background:var(--surface);border-bottom:1px solid var(--border);justify-content:space-between;align-items:center;margin:0 -22px;padding:14px 14px 12px 22px;display:flex;position:sticky;top:0}.progress__header h2{margin:0;font-size:1.1rem}.progress__overview{grid-template-columns:1.7fr repeat(3,1fr);gap:10px;margin-top:18px;display:grid}.tile{border:1px solid var(--border);background:var(--surface-2);border-radius:12px;padding:12px 14px}.tile--goal{align-items:center;gap:12px;display:flex}.tile__value{font-variant-numeric:tabular-nums;font-size:1.5rem;font-weight:700;line-height:1.2}.tile__of{color:var(--muted);font-size:1rem;font-weight:500}.tile__label{color:var(--muted);font-size:.8rem}.progress__section{margin-top:22px}.progress__section h3{letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin:0 0 10px;font-size:.75rem;font-weight:650}.progress__count{color:var(--text);margin-left:4px}.bars{flex-direction:column;gap:6px;margin:0;padding:0;list-style:none;display:flex}.bar{font-variant-numeric:tabular-nums;grid-template-columns:9.5rem 1fr 3rem 3.5rem;align-items:center;gap:10px;font-size:.875rem;display:grid}.bar__track{background:var(--surface-2);border:1px solid var(--border);border-radius:999px;height:8px;overflow:hidden}.bar__fill{background:var(--accent);border-radius:999px;height:100%;display:block}.bar__value{text-align:right;font-weight:650}.bar__count{color:var(--muted);font-size:.8rem}.bar--empty{color:var(--muted)}.badges{grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:8px;margin:0;padding:0;list-style:none;display:grid}.badge{border:1px solid var(--border);color:var(--muted);border-radius:12px;align-items:flex-start;gap:12px;padding:10px 12px;display:flex}.badge__icon{background:var(--surface-2);border:1px dashed var(--border);border-radius:50%;flex:none;place-items:center;width:36px;height:36px;display:grid}.badge__text{flex-direction:column;font-size:.82rem;display:flex}.badge__text strong{font-size:.9rem}.badge--unlocked{border-color:var(--accent);background:var(--accent-soft);color:var(--text)}.badge--unlocked .badge__icon{background:var(--accent);color:var(--accent-text);border:none}.badge__date{color:var(--accent);margin-top:2px;font-size:.75rem;font-weight:600}@media (width<=600px){.progress__overview{grid-template-columns:repeat(3,1fr)}.tile--goal{grid-column:1/-1}}@media (width<=480px){.stats__today .goal-ring{display:none}.tile{padding:10px}.tile__value{font-size:1.25rem}.bar{grid-template-columns:7rem 1fr 2.6rem}.bar__count{display:none}}@media (prefers-reduced-motion:reduce){*,:before,:after{transition:none!important;animation:none!important}}.ghost-button{color:var(--muted);background:0 0;border:none;border-radius:7px;padding:6px 10px;font-size:.85rem}.ghost-button:hover{background:var(--surface-2);color:var(--text)}.ghost-button--danger,.ghost-button--danger:hover{color:var(--wrong)}.header__actions{align-items:stretch;gap:8px;display:flex}.menu{display:flex;position:relative}.menu__trigger,.header-button{border:1px solid 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var(--radius) var(--radius);justify-content:space-between;align-items:center;gap:8px;padding:8px 10px 8px 16px;font-size:.85rem;display:flex}.menu__footer>.ghost-button:only-child{margin-left:-10px}.menu__footer-actions{gap:4px;display:flex}.layout{grid-template-columns:minmax(0,600px) minmax(320px,1fr);align-items:start;gap:28px;display:grid}@media (width<=880px){.layout{grid-template-columns:minmax(0,1fr);gap:20px}.header__actions{width:100%}.stats{flex:1}.stats>div{min-width:0;padding:2px 4px}.menu__trigger,.header-button{width:44px}.stats>div{flex:1}}.board-frame{box-shadow:var(--shadow-board);border-radius:6px;position:relative}.board-frame--loading .board{filter:blur(3px)saturate(.5)}.overlay{place-items:center;font-weight:600;display:grid;position:absolute;inset:0}.board{aspect-ratio:1;-webkit-user-select:none;user-select:none;border-radius:6px;grid-template-rows:repeat(8,1fr);grid-template-columns:repeat(8,1fr);width:100%;display:grid;overflow:hidden;container-type:inline-size}.square{position:relative}.square--light{background:var(--sq-light)}.square--dark{background:var(--sq-dark)}.square--highlight:before,.square--selected:before{content:"";background:var(--sq-highlight);position:absolute;inset:0}.square--selected:before{background:var(--sq-selected)}.board--clickable .square{cursor:pointer}.board--clickable .square:hover:after{content:"";position:absolute;inset:0;box-shadow:inset 0 0 0 3px #ffffffb3}.piece{pointer-events:none;width:100%;height:100%;position:absolute;inset:0}.coord{pointer-events:none;font-size:max(9px,2.4cqi);font-weight:700;line-height:1;position:absolute}.square--light .coord{color:var(--sq-dark)}.square--dark .coord{color:var(--sq-light)}.coord--rank{top:4%;left:5%}.coord--file{bottom:4%;right:5%}.board-footer{justify-content:center;min-height:40px;margin-top:14px;display:flex}.board-caption{color:var(--muted);align-self:center;margin:0;font-size:.875rem}.stepper{background:var(--surface);border:1px solid var(--border);border-radius:10px;align-items:center;gap:4px;padding:3px;display:flex}.stepper__label{text-align:center;font-variant-numeric:tabular-nums;min-width:112px;color:var(--muted);font-size:.875rem}.icon-button{width:36px;height:34px;color:var(--text);background:0 0;border:none;border-radius:7px;place-items:center;display:grid}.icon-button:hover:not(:disabled){background:var(--surface-2)}.icon-button:disabled{opacity:.3}.panel{flex-direction:column;gap:16px;display:flex}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow-card);padding:18px}.exercise{padding:0;overflow:hidden}.exercise__meta{border-bottom:1px solid var(--border);flex-wrap:wrap;justify-content:space-between;align-items:center;gap:6px 12px;padding:14px 18px;font-size:.85rem;display:flex}.turn{align-items:center;gap:8px;font-weight:600;display:inline-flex}.turn__dot{border:1.5px solid #1c1b19;border-radius:50%;width:12px;height:12px}.turn--w .turn__dot{background:#fff}.turn--b .turn__dot{background:#1c1b19;border-color:#6e6a63}.exercise__link{font-weight:500}.moves{border-collapse:collapse;font-variant-numeric:tabular-nums;width:100%}.moves tr:nth-child(2n){background:var(--surface-2)}.moves th{text-align:left;width:3.5rem;color:var(--muted);padding:0 0 0 18px;font-weight:500}.moves td{width:calc(50% - 1.75rem);padding:3px 6px 3px 0}.move{text-align:left;background:0 0;border:none;border-radius:6px;width:100%;padding:6px 10px;font-size:1.08rem;font-weight:650;display:block}button.move:hover{background:var(--accent-soft)}.move--current,button.move--current:hover{background:var(--accent);color:var(--accent-text)}.move--empty{color:var(--muted);font-weight:500}.question{border-top:1px solid var(--border);padding:16px 18px 18px}.question__label{letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin:0 0 6px;font-size:.7rem;font-weight:650}.question__prompt{margin:0 0 16px;font-size:1.05rem;font-weight:550}.question__hint{color:var(--muted);margin:-12px 0 16px;font-size:.85rem}.exercise__actions{border-top:1px solid var(--border);background:var(--surface-2);flex-wrap:wrap;align-items:center;gap:10px 16px;padding:14px 18px;display:flex}.kbd-hint{color:var(--muted);font-size:.8rem}kbd{border:1px solid var(--border);background:var(--surface);min-width:1.6em;font:inherit;text-align:center;border-bottom-width:2px;border-radius:5px;margin:0 1px;padding:1px 5px;font-size:.75rem;display:inline-block}.button{border:1px solid var(--border);background:var(--surface);border-radius:9px;justify-content:center;align-items:center;min-width:88px;height:40px;padding:0 18px;font-weight:600;transition:background-color .12s,border-color .12s;display:inline-flex}.button:hover:not(:disabled){border-color:var(--accent);background:var(--accent-soft)}.button--primary{border-color:var(--accent);background:var(--accent);color:var(--accent-text)}.button--primary:hover:not(:disabled){border-color:var(--accent-hover);background:var(--accent-hover)}.button:disabled{opacity:.45}.button--small{min-width:0;height:32px;padding:0 12px;font-size:.85rem}.button-row{flex-wrap:wrap;gap:8px;display:flex}.button--square{font-variant-numeric:tabular-nums;min-width:52px;padding:0 12px;font-size:1.05rem}.square-answer{flex-direction:column;gap:12px;display:flex}.mini-board{width:min(100%,288px);box-shadow:var(--shadow-board);border-radius:6px}.material-answer{flex-direction:column;gap:12px;display:flex}.material-side__label{letter-spacing:.06em;text-transform:uppercase;color:var(--muted);margin-bottom:6px;font-size:.75rem;font-weight:650}.material-row{grid-template-columns:repeat(5,minmax(0,1fr));gap:6px;display:grid}.counter{border:1px solid var(--border);background:var(--surface-2);border-radius:10px;flex-direction:column;align-items:center;gap:2px;padding:6px 4px;transition:background-color .12s,border-color .12s;display:flex}.counter--changed{border-color:var(--accent);background:var(--accent-soft)}.counter__piece{width:34px;height:34px}.counter__value{font-variant-numeric:tabular-nums;font-size:1.1rem;font-weight:700;line-height:1.2;position:relative}.counter__diff{color:var(--accent);font-size:.7rem;font-weight:650;position:absolute;top:1px;left:calc(100% + 3px)}.counter__buttons{gap:4px;margin-top:4px;display:flex}.counter__buttons button{border:1px solid var(--border);background:var(--surface);border-radius:7px;place-items:center;width:26px;height:26px;padding:0;font-size:1rem;font-weight:600;line-height:1;display:grid}.counter__buttons button:hover:not(:disabled){border-color:var(--accent);color:var(--accent)}.counter__buttons button:disabled{opacity:.35}.material-answer .button-row{margin-top:4px}.material-answer--result{margin:12px 0 0 34px}.material-answer--result .counter{background:var(--surface)}.counter--wrong{border-color:var(--wrong)}.counter__yours{color:var(--wrong);font-size:.7rem;font-weight:600;text-decoration:line-through}@media (width<=480px){.material-answer--result{margin-left:0}.counter__piece{width:28px;height:28px}}.result{border-radius:10px;padding:12px 14px}.result--correct{background:var(--correct-bg);--result:var(--correct)}.result--wrong{background:var(--wrong-bg);--result:var(--wrong)}.result__head{align-items:center;gap:10px;display:flex}.result__icon{background:var(--result);color:#fff;border-radius:50%;flex:none;place-items:center;width:24px;height:24px;font-size:.8rem;font-weight:800;display:grid}.result__title{color:var(--result);font-weight:650}.result__explanation{margin:6px 0 0 34px}.error{color:var(--wrong)}.field__label{margin-bottom:8px;font-size:.875rem;font-weight:600;display:block}.field__hint{color:var(--muted);font-weight:400}.segmented{background:var(--surface-2);border:1px solid var(--border);border-radius:9px;padding:3px;display:flex}.segmented button{font-variant-numeric:tabular-nums;height:32px;color:var(--muted);background:0 0;border:none;border-radius:6px;flex:1;font-weight:600}.segmented button:hover:not(.is-active){color:var(--text)}.segmented button.is-active{background:var(--surface);color:var(--text);box-shadow:0 1px 2px #0000001f, 0 0 0 1px var(--border)}.chips{flex-wrap:wrap;gap:8px;display:flex}.chip{border:1px solid var(--border);background:var(--surface);height:34px;color:var(--muted);border-radius:999px;padding:0 14px;font-size:.875rem;font-weight:500}.chip:hover:not(:disabled){color:var(--text)}.chip:disabled{cursor:not-allowed}.chip.is-active{border-color:var(--accent);background:var(--accent-soft);color:var(--text)}.chip.is-active:before{content:"✓ ";color:var(--accent);font-weight:700}.footer{text-align:center;color:var(--muted);margin-top:32px;font-size:.8rem}