:root{--brand:#4f46e5;--brand-dark:#4338ca;--brand-tint:#eef2ff;--bg:#f8fafc;--surface:#fff;--text:#1e293b;--muted:#64748b;--border:#e2e8f0;--success:#16a34a;--success-tint:#f0fdf4;--danger:#dc2626;--danger-tint:#fef2f2;--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;font-family:system-ui,-apple-system,Segoe UI,Arial,sans-serif;font-size:120%}@media (prefers-color-scheme:dark){:root:not([data-theme=light]){--brand:#818cf8;--brand-dark:#a5b4fc;--brand-tint:#1e1b4b;--bg:#0f172a;--surface:#1e293b;--text:#e2e8f0;--muted:#94a3b8;--border:#334155;--success:#4ade80;--success-tint:#052e16;--danger:#f87171;--danger-tint:#450a0a;--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark}}:root[data-theme=dark]{--brand:#818cf8;--brand-dark:#a5b4fc;--brand-tint:#1e1b4b;--bg:#0f172a;--surface:#1e293b;--text:#e2e8f0;--muted:#94a3b8;--border:#334155;--success:#4ade80;--success-tint:#052e16;--danger:#f87171;--danger-tint:#450a0a;--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark}:root[data-font-scale=large]{font-size:140%}:root[data-font-scale=xlarge]{font-size:160%}*{box-sizing:border-box}body{background:var(--bg);color:var(--text);margin:0}button,input,textarea{font-family:inherit;font-size:1rem}a{color:inherit;text-decoration:none}.app-shell{flex-direction:column;min-height:100dvh;display:flex}.app-content{flex:1;width:100%;max-width:640px;margin:0 auto;padding:16px 16px 88px}.navbar{inset-inline:0;background:var(--surface);border-top:1px solid var(--border);padding:10px 0 calc(10px + env(safe-area-inset-bottom));z-index:10;justify-content:space-around;display:flex;position:fixed;bottom:0}.navbar a{color:var(--muted);padding:6px 10px;font-size:.9rem}.navbar a.active{color:var(--brand);font-weight:600}.page-loading{text-align:center;color:var(--muted);padding:40px}.update-overlay{background:var(--bg);color:var(--text);z-index:1000;justify-content:center;align-items:center;font-weight:600;display:flex;position:fixed;inset:0}.subtitle{color:var(--muted);margin-top:-8px}.auth-page,.onboarding-page{text-align:center;flex-direction:column;align-items:stretch;gap:12px;padding-top:40px;display:flex}.auth-form{flex-direction:column;gap:10px;margin-top:12px;display:flex}input,textarea{border:1px solid var(--border);background:var(--surface);color:var(--text);border-radius:8px;width:100%;padding:10px 12px}.btn-primary,.btn-secondary{cursor:pointer;border:none;border-radius:10px;padding:12px 16px;font-weight:600}.btn-primary{background:var(--brand);color:#fff}.btn-primary:disabled{opacity:.5;cursor:not-allowed}.btn-secondary{background:var(--surface);border:1px solid var(--border);color:var(--text)}.link-button{color:var(--brand);cursor:pointer;background:0 0;border:none;padding:8px}.form-error{color:var(--danger);margin:0}.form-success{color:var(--success);margin:0}.category-grid{grid-template-columns:repeat(2,1fr);gap:10px;margin:16px 0;display:grid}.category-chip{border:1px solid var(--border);background:var(--surface);cursor:pointer;border-radius:12px;align-items:center;gap:8px;padding:14px;display:flex}.category-chip.selected{border-color:var(--brand);background:var(--brand-tint);color:var(--brand-dark)}.category-icon{font-size:1.3rem}.topic-list{flex-direction:column;gap:12px;margin-top:16px;display:flex}.topic-card{background:var(--surface);border:1px solid var(--border);border-radius:14px;padding:16px;display:block}.topic-card.learned{opacity:.75}.topic-card-header{justify-content:space-between;align-items:center;margin-bottom:6px;display:flex}.topic-card-category{color:var(--muted);font-size:.85rem}.topic-card-badge{color:var(--success);font-size:.8rem;font-weight:600}.topic-card h3{margin:4px 0}.topic-card p{color:var(--muted);margin:0}.topic-page{flex-direction:column;gap:12px;display:flex}.topic-explanation{line-height:1.7}.topic-actions{flex-wrap:wrap;gap:10px;margin-top:8px;display:flex}.topic-done{text-align:center;padding:40px 0}.quiz{flex-direction:column;gap:12px;display:flex}.quiz-progress{color:var(--muted);margin:0}.quiz-choices{flex-direction:column;gap:8px;display:flex}.quiz-choice{border:1px solid var(--border);background:var(--surface);text-align:start;cursor:pointer;border-radius:10px;padding:12px 14px}.quiz-choice.correct{border-color:var(--success);background:var(--success-tint)}.quiz-choice.incorrect{border-color:var(--danger);background:var(--danger-tint)}.quiz-choice:disabled{cursor:default}.draft-list{flex-direction:column;gap:16px;margin-top:16px;display:flex}.draft-card{background:var(--surface);border:1px solid var(--border);border-radius:14px;flex-direction:column;gap:8px;padding:16px;display:flex}.draft-meta{color:var(--muted);margin:0;font-size:.9rem}.settings-page,.admin-page,.history-page,.home-page{flex-direction:column;display:flex}.option-row{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px;padding:10px 0;display:flex}.option-label{color:var(--text)}.segmented{border:1px solid var(--border);border-radius:10px;display:flex;overflow:hidden}.segmented-btn{background:var(--surface);color:var(--muted);cursor:pointer;border:none;border-inline-start:1px solid var(--border);padding:8px 12px}.segmented-btn:first-child{border-inline-start:none}.segmented-btn.active{background:var(--brand);color:#fff}