:root{--bg: #f0f9ff;--surface: #ffffff;--surface-2: #e0f2fe;--text: #0f172a;--text-soft: #475569;--accent: #0ea5e9;--accent-soft: #e0f2fe;--success: #16a34a;--success-soft: #dcfce7;--danger: #ef4444;--danger-soft: #fee2e2;--warn: #f59e0b;--border: #cce4f6;--shadow: 0 6px 18px rgba(2, 32, 71, .08);--radius: 18px;--radius-lg: 26px}[data-theme=dark]{--bg: #0b1220;--surface: #111a2c;--surface-2: #0b1424;--text: #e2e8f0;--text-soft: #94a3b8;--accent: #38bdf8;--accent-soft: #0c2238;--border: #1f2a44;--success-soft: #0c2a17;--danger-soft: #2a1212;--shadow: 0 8px 24px rgba(0, 0, 0, .5)}@media (prefers-color-scheme: dark){:root:not([data-theme=light]){--bg: #0b1220;--surface: #111a2c;--surface-2: #0b1424;--text: #e2e8f0;--text-soft: #94a3b8;--accent: #38bdf8;--accent-soft: #0c2238;--border: #1f2a44;--success-soft: #0c2a17;--danger-soft: #2a1212;--shadow: 0 8px 24px rgba(0, 0, 0, .5)}}*{box-sizing:border-box}html,body,#root{margin:0;padding:0;height:100%;background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,Segoe UI,Roboto,"Apple Color Emoji","Segoe UI Emoji",sans-serif;-webkit-font-smoothing:antialiased;-webkit-tap-highlight-color:transparent;overscroll-behavior:none;-webkit-user-select:none;user-select:none}button{font-family:inherit;cursor:pointer}input{font-family:inherit}.app{min-height:100%;display:flex;flex-direction:column}.topbar{display:flex;align-items:center;justify-content:space-between;padding-top:calc(clamp(12px,1.4vw,18px) + env(safe-area-inset-top,0px));padding-right:calc(clamp(16px,2.4vw,28px) + env(safe-area-inset-right,0px));padding-bottom:clamp(12px,1.4vw,18px);padding-left:calc(clamp(16px,2.4vw,28px) + env(safe-area-inset-left,0px));border-bottom:1px solid var(--border);background:var(--surface);position:sticky;top:0;z-index:10}.topbar .title{font-weight:700;font-size:clamp(18px,2.2vw,24px);display:flex;gap:10px;align-items:center}.topbar .brand-logo{width:clamp(28px,3vw,38px);height:clamp(28px,3vw,38px);border-radius:8px;display:block}.topbar .brand-btn{display:inline-flex;align-items:center;gap:10px;background:transparent;border:0;padding:4px 6px;border-radius:12px;color:inherit;font-weight:inherit;font-size:inherit;cursor:pointer}.topbar .brand-btn:hover:not(:disabled){background:var(--surface-2)}.topbar .brand-btn:disabled{cursor:default;opacity:1}.topbar .user-pill{display:inline-flex;align-items:center;gap:6px;background:var(--surface-2);border:1px solid var(--border);border-radius:999px;padding:4px 12px;font-size:clamp(13px,1.4vw,16px);color:var(--text-soft);font-weight:600;cursor:pointer}.topbar .user-pill:hover:not(:disabled){border-color:var(--accent);color:var(--text)}.topbar .user-pill:disabled{cursor:default}.topbar .actions{display:flex;gap:clamp(8px,1vw,12px)}.icon-btn{background:var(--surface-2);color:var(--text);border:1px solid var(--border);border-radius:999px;padding:clamp(8px,1.2vw,12px) clamp(12px,1.6vw,18px);font-size:clamp(16px,1.6vw,18px);display:inline-flex;align-items:center;gap:6px;min-height:40px}.icon-btn:hover{background:var(--accent-soft)}.icon-btn[aria-pressed=true]{background:var(--accent-soft);color:var(--accent);border-color:var(--accent)}.streak-chip{display:inline-flex;align-items:center;gap:4px;background:#f59e0b1f;color:#b45309;border:1px solid rgba(245,158,11,.45);border-radius:999px;padding:6px 12px;font-weight:800;font-size:clamp(13px,1.4vw,16px);min-height:36px;cursor:pointer}[data-theme=dark] .streak-chip{color:#fbbf24;background:#f59e0b29}.streak-chip:hover:not(:disabled){filter:brightness(1.05)}.streak-chip:disabled{cursor:default;opacity:.7}.streak-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:14px;margin-bottom:14px;box-shadow:var(--shadow)}.streak-card-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}.streak-card-stat{text-align:center}.streak-card-num{font-size:28px;font-weight:800;color:var(--accent)}.streak-card-lbl{font-size:12px;color:var(--text-soft);text-transform:uppercase;letter-spacing:.5px}.streak-card-hint{margin-top:10px;text-align:center;font-size:13px;color:var(--text-soft)}.trophy-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:12px}.trophy-tile{background:var(--surface);border:1.5px solid var(--border);border-radius:var(--radius);padding:14px 10px;text-align:center;display:flex;flex-direction:column;gap:4px}.trophy-tile.got{border-color:var(--accent)}.trophy-tile.locked{opacity:.55}.trophy-emoji{font-size:36px;line-height:1}.trophy-label{font-weight:800;font-size:14px}.trophy-desc{font-size:12px;color:var(--text-soft)}.badges-earned{margin:10px auto 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var(--border);padding-top:10px;color:var(--accent)}.answer-placeholder{color:var(--text-soft);opacity:.5}.aid{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;gap:14px;margin-top:14px}.aid-op{font-size:clamp(22px,3.4vw,32px);font-weight:800;color:var(--text-soft)}.dot-group{display:inline-flex;flex-wrap:wrap;gap:6px;padding:10px;border-radius:16px;background:#0ea5e914;max-width:220px}.dot{width:clamp(16px,2.4vw,22px);height:clamp(16px,2.4vw,22px);border-radius:50%;display:inline-block}.dot-a{background:#0ea5e9}.dot-b{background:#f97316}.dot-off{background:transparent;border:2px dashed var(--text-soft);opacity:.55;position:relative}.dot-off:after{content:"×";position:absolute;top:0;right:0;bottom:0;left:0;display:grid;place-items:center;color:var(--text-soft);font-weight:800;font-size:14px}.aid-sub{gap:8px;padding:10px;background:#0ea5e914;border-radius:16px;max-width:320px;margin-left:auto;margin-right:auto}.aid-compare{gap:32px;align-items:flex-end}.dot-stack{display:inline-flex;flex-direction:column;align-items:center;gap:6px}.dot-stack-num{font-weight:800;font-size:18px;color:var(--text-soft)}.dot-stack-col{display:inline-flex;flex-direction:column-reverse;gap:4px;padding:8px;border-radius:12px;background:#0ea5e914;min-height:28px}.help-row{display:flex;justify-content:center}.help-btn{background:var(--warn)}.hint-ladder{display:flex;flex-direction:column;align-items:center;gap:10px}.hint-actions{display:flex;gap:8px;align-items:center;flex-wrap:wrap;justify-content:center}.hint-list{width:100%;max-width:520px;margin:0;padding:12px 16px 12px 32px;background:#f59e0b14;border:1px solid rgba(245,158,11,.25);border-radius:var(--radius);display:flex;flex-direction:column;gap:6px;font-size:15px;line-height:1.5}.numpad{display:grid;grid-template-columns:repeat(3,1fr);gap:clamp(8px,1.5vw,12px);margin-top:4px}.numpad .key{background:var(--surface);border:2px solid var(--border);border-radius:var(--radius);font-size:clamp(22px,3.6vw,30px);font-weight:800;color:var(--text);height:clamp(56px,9vw,72px)}.numpad .key:active{transform:translateY(1px);background:var(--surface-2)}.numpad .key-aux{color:var(--accent)}.numpad .key-back{background:var(--surface-2)}.numpad .key-clear{color:var(--danger)}.numpad .key-fullrow{grid-column:span 3}.numpad .key-submit{grid-column:span 3;background:var(--accent);color:#fff;border:0;font-size:clamp(20px,2.4vw,24px);height:clamp(60px,9vw,72px)}.numpad .key-submit:disabled{opacity:.5}.numpad .key-submit.fb-correct{background:var(--success)}.numpad 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6px;font-size:12px}.help-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#0f172a8c;display:flex;align-items:center;justify-content:center;z-index:60;padding:14px}.help-card{width:min(520px,100%);background:var(--surface);color:var(--text);border-radius:var(--radius-lg);padding:18px;box-shadow:var(--shadow)}.help-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:8px}.help-title{font-weight:800;font-size:20px}.help-problem{background:var(--accent-soft);border:1px solid var(--border);border-radius:var(--radius);padding:14px;text-align:center;font-size:26px;font-weight:800;margin-bottom:12px;white-space:pre-line}.help-steps{margin:0 0 12px;padding-left:22px;font-size:16px;line-height:1.5;display:flex;flex-direction:column;gap:6px}.help-actions{display:flex;gap:8px;justify-content:flex-end;flex-wrap:wrap}.help-error{color:var(--danger);margin-top:8px;font-size:13px}.modal-scrim{position:fixed;top:0;right:0;bottom:0;left:0;background:#0006;display:flex;align-items:center;justify-content:center;z-index:50;padding:14px}.modal-card{width:min(460px,100%);background:var(--surface);color:var(--text);border-radius:var(--radius-lg);padding:18px;box-shadow:var(--shadow);max-height:90vh;overflow-y:auto}.settings-row{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px 0;border-bottom:1px solid var(--border)}.settings-row:last-of-type{border-bottom:0}.settings-row .label{font-weight:700}.settings-row .desc{font-size:13px;color:var(--text-soft)}.toggle{width:48px;height:28px;border-radius:999px;background:var(--surface-2);border:1px solid var(--border);position:relative;transition:background .15s ease}.toggle:after{content:"";position:absolute;top:2px;left:2px;width:22px;height:22px;border-radius:50%;background:#fff;box-shadow:0 1px 2px #00000040;transition:transform .15s ease}.toggle[aria-pressed=true]{background:var(--accent);border-color:var(--accent)}.toggle[aria-pressed=true]:after{transform:translate(20px)}