:root{--bg: #0f1115;--surface: #1a1d24;--surface-2: #232733;--text: #eef1f6;--text-dim: #9aa3b2;--border: #2c3140;--accent: #7aa2ff;--correct: #2f9e57;--correct-ink: #eafff1;--wrong: #d1435b;--wrong-ink: #ffeef1;--revealed: #3a6b4c;--radius: 12px;--tap: 44px;--font: "Segoe UI", system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;--num-font: "SF Mono", "JetBrains Mono", "Roboto Mono", ui-monospace, "Courier New", monospace}:root.color-blind{--correct: #2b7bd6;--correct-ink: #eaf4ff;--wrong: #e07a1f;--wrong-ink: #fff4e8;--revealed: #2f5a86}:root.high-contrast{--bg: #000;--surface: #0a0a0a;--surface-2: #141414;--text: #fff;--text-dim: #cfcfcf;--border: #6a6a6a;--correct: #12b85a;--wrong: #ff2d55}*{box-sizing:border-box}html,body{margin:0;height:100%;background:var(--bg);color:var(--text);font-family:var(--font);-webkit-font-smoothing:antialiased;-webkit-tap-highlight-color:transparent;overscroll-behavior:none}#app{display:flex;flex-direction:column;min-height:100%;max-width:480px;margin:0 auto;padding:env(safe-area-inset-top) 0 env(safe-area-inset-bottom)}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}.app-header{display:flex;align-items:center;gap:8px;padding:10px 12px;border-bottom:1px solid var(--border)}.brand{flex:1;text-align:center;font-size:1.35rem;font-weight:700;letter-spacing:.02em;margin:0}.header-actions{display:flex;gap:2px}.icon-btn{display:inline-flex;align-items:center;justify-content:center;min-width:var(--tap);min-height:var(--tap);background:transparent;color:var(--text);border:none;border-radius:10px;cursor:pointer}.icon-btn:hover{background:var(--surface-2)}.icon-btn:focus-visible,.cell:focus-visible,.btn:focus-visible,.menu-item:focus-visible{outline:3px solid var(--accent);outline-offset:2px}#screen{flex:1;display:flex;flex-direction:column;padding:10px 12px 16px}.play-head{display:flex;align-items:baseline;gap:8px;justify-content:center;color:var(--text-dim);font-size:.8rem;margin-bottom:8px}.puzzle-no{font-weight:700;color:var(--text)}.archive-badge{background:var(--surface-2);border:1px solid var(--border);border-radius:999px;padding:1px 8px;font-size:.7rem;text-transform:uppercase}.play-status{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px;gap:12px}.divisor-banner{text-align:center;padding:8px 12px;margin-bottom:12px;background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius);font-size:1.05rem}.divisor-banner strong{color:var(--accent);font-variant-numeric:tabular-nums}.divisor-banner .find-all{color:var(--text-dim);font-size:.9rem}.menu-tag{margin-left:8px;font-size:.7rem;color:var(--text-dim);border:1px solid var(--border);border-radius:999px;padding:1px 7px}.stats-mode{text-align:center;color:var(--text-dim);font-size:.85rem;margin-bottom:12px}.counter{display:flex;align-items:center;gap:8px}.counter-label{font-size:.75rem;color:var(--text-dim);text-transform:uppercase;letter-spacing:.04em}.pips{display:flex;gap:5px}.pip{width:12px;height:12px;border-radius:50%;border:2px solid var(--border);background:transparent;transition:background .2s,border-color .2s}.pips.primes .pip.filled{background:var(--correct);border-color:var(--correct)}.pips.mistakes .pip.filled{background:var(--wrong);border-color:var(--wrong)}.grid{display:grid;grid-template-columns:repeat(var(--n),1fr);gap:7px;width:100%;aspect-ratio:1 / 1;margin:auto 0}.cell{position:relative;display:flex;flex-direction:column;align-items:center;justify-content:center;min-width:var(--tap);min-height:var(--tap);padding:2px;background:var(--surface);color:var(--text);border:1px solid var(--border);border-radius:10px;font-family:var(--num-font);font-variant-numeric:tabular-nums;font-size:clamp(.9rem,4.6vw,1.35rem);font-weight:600;cursor:pointer;user-select:none;transition:transform .08s}.cell:not([disabled]):active{transform:scale(.96)}.cell .num{line-height:1}.cell .glyph{font-size:.7em;line-height:1;margin-top:1px}.cell .factor{font-size:.56em;font-weight:500;opacity:.9;margin-top:1px;letter-spacing:-.02em}.cell.correct{background:var(--correct);border-color:var(--correct);color:var(--correct-ink)}.cell.wrong{background:var(--wrong);border-color:var(--wrong);color:var(--wrong-ink)}.cell.revealed-prime{background:transparent;border:2px solid var(--correct);color:var(--text)}.cell.revealed-composite{background:var(--surface);color:var(--text-dim);opacity:.6}@keyframes pop{0%{transform:scale(1)}45%{transform:scale(1.12)}to{transform:scale(1)}}@keyframes shake{0%,to{transform:translate(0)}20%{transform:translate(-5px)}40%{transform:translate(5px)}60%{transform:translate(-3px)}80%{transform:translate(3px)}}.anim-pop{animation:pop .28s ease-out}.anim-shake{animation:shake .34s ease-in-out}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:var(--tap);padding:10px 18px;background:var(--surface-2);color:var(--text);border:1px solid var(--border);border-radius:var(--radius);font-size:1rem;font-weight:600;cursor:pointer}.btn:hover{border-color:var(--accent)}.btn.primary{background:var(--accent);color:#0b1020;border-color:var(--accent)}.btn.big{flex:1;font-size:1.1rem;padding:16px}.btn.big.prime{background:var(--correct);color:var(--correct-ink);border:none}.btn.big.not-prime{background:var(--wrong);color:var(--wrong-ink);border:none}.btn.flash{opacity:.85}.link{background:none;border:none;color:var(--accent);font-size:.95rem;cursor:pointer;padding:8px;min-height:var(--tap)}.link.rapid-link{color:var(--text-dim)}.overlay{position:fixed;inset:0;background:#0009;display:flex;align-items:flex-end;justify-content:center;z-index:50;animation:fade .16s ease-out}@keyframes fade{0%{opacity:0}to{opacity:1}}.modal{width:100%;max-width:480px;max-height:92vh;overflow-y:auto;background:var(--surface);border-top-left-radius:18px;border-top-right-radius:18px;border:1px solid var(--border);animation:slideup .2s ease-out}@keyframes slideup{0%{transform:translateY(16px)}to{transform:translateY(0)}}.modal-head{position:sticky;top:0;display:flex;align-items:center;justify-content:space-between;padding:14px 14px 10px;background:var(--surface);border-bottom:1px solid var(--border)}.modal-head h2{margin:0;font-size:1.1rem}.modal-content{padding:16px}@media(min-width:520px){.overlay{align-items:center}.modal{border-radius:18px}}.end-body{display:flex;flex-direction:column;align-items:center;gap:14px;text-align:center}.outcome-tier{font-size:1.6rem;font-weight:800}.outcome-tier.flawless{color:var(--correct)}.outcome-tier.solved{color:var(--accent)}.outcome-tier.failed{color:var(--wrong)}.outcome-msg{color:var(--text-dim);margin:0}.end-body .btn.primary{width:100%}.next-countdown{color:var(--text-dim);font-size:.9rem}.countdown{font-family:var(--num-font);font-variant-numeric:tabular-nums;color:var(--text)}.end-links{display:flex;flex-direction:column;gap:2px;width:100%}.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}.stats-grid.compact{grid-template-columns:repeat(4,1fr);width:100%}.stat{text-align:center}.stat-val{font-size:1.5rem;font-weight:800;font-variant-numeric:tabular-nums}.stat-label{font-size:.68rem;color:var(--text-dim);text-transform:uppercase;letter-spacing:.03em}.histogram{margin-top:20px}.histogram h3{font-size:.9rem;margin:0 0 10px}.histo-row{display:flex;align-items:center;gap:8px;margin-bottom:6px}.histo-label{width:2.5em;font-size:.85rem;color:var(--text-dim)}.histo-bar-wrap{flex:1}.histo-bar{min-width:1.6em;padding:3px 8px;background:var(--accent);color:#0b1020;border-radius:6px;font-size:.8rem;font-weight:700;text-align:right}.histo-bar.fail{background:var(--wrong);color:var(--wrong-ink)}.empty{color:var(--text-dim);text-align:center;padding:24px 0}.help-cards,.onboarding{display:flex;flex-direction:column;gap:14px}.help-card{position:relative;background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius);padding:16px 16px 16px 52px}.help-card .card-num{position:absolute;left:14px;top:16px;width:26px;height:26px;display:flex;align-items:center;justify-content:center;background:var(--accent);color:#0b1020;border-radius:50%;font-weight:800;font-size:.85rem}.help-card h3{margin:0 0 6px;font-size:1rem}.help-card p{margin:0;color:var(--text-dim);font-size:.92rem}.cheat{background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius);padding:16px}.cheat h3{margin:0 0 8px;font-size:1rem}.cheat ul{margin:0;padding-left:18px;color:var(--text-dim);font-size:.9rem;line-height:1.7}.dots{display:flex;gap:6px;justify-content:center}.dot{width:8px;height:8px;border-radius:50%;background:var(--border)}.dot.on{background:var(--accent)}.onboard-actions{display:flex;align-items:center;justify-content:space-between}.menu{display:flex;flex-direction:column}.menu hr{border:none;border-top:1px solid var(--border);margin:6px 0}.menu-item{text-align:left;background:none;border:none;color:var(--text);font-size:1rem;padding:12px 8px;min-height:var(--tap);cursor:pointer;border-radius:8px}.menu-item:hover{background:var(--surface-2)}.menu-item.active{color:var(--accent);font-weight:700}.settings{display:flex;flex-direction:column;gap:4px}.setting-row{display:flex;align-items:center;justify-content:space-between;padding:12px 4px;min-height:var(--tap);cursor:pointer}.setting-row input{width:22px;height:22px;accent-color:var(--accent)}.archive-sub{color:var(--text-dim);font-size:.9rem;margin:0 0 12px}.archive-list{display:flex;flex-direction:column;gap:6px}.archive-row{display:grid;grid-template-columns:3em 1fr auto auto;align-items:center;gap:10px;background:var(--surface-2);border:1px solid var(--border);border-radius:10px;padding:10px 12px;min-height:var(--tap);color:var(--text);cursor:pointer;text-align:left}.archive-row:hover{border-color:var(--accent)}.archive-no{font-weight:700;font-variant-numeric:tabular-nums}.archive-date{color:var(--text-dim);font-size:.85rem}.archive-tier{font-size:.7rem;color:var(--text-dim)}.archive-done{color:var(--correct);font-size:.8rem;font-weight:700}.archive-play{color:var(--accent);font-size:.8rem;font-weight:700}.rapid{display:flex;flex-direction:column;align-items:center;gap:18px;text-align:center}.rapid-sub{color:var(--text-dim);margin:0}.rapid-number{font-family:var(--num-font);font-variant-numeric:tabular-nums;font-size:4rem;font-weight:800;letter-spacing:.02em}.rapid-btns{display:flex;gap:12px;width:100%}.rapid-scores,.rapid-final{display:flex;gap:18px;color:var(--text-dim);font-variant-numeric:tabular-nums}.rapid-miss{color:var(--text-dim);margin:0}@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important}}@media(prefers-color-scheme:light){:root:not(.high-contrast){--bg: #f7f8fb;--surface: #ffffff;--surface-2: #eef1f6;--text: #14171f;--text-dim: #5b6472;--border: #d6dbe4;--accent: #3b62d6;--correct-ink: #ffffff;--wrong-ink: #ffffff}}