:root{--blue: #2563eb;--blue-dk: #1d4ed8;--green: #16a34a;--amber: #d97706;--red: #dc2626;--gray-50: #f8fafc;--gray-100:#f1f5f9;--gray-300:#cbd5e1;--gray-500:#64748b;--gray-700:#334155;--gray-900:#0f172a;--radius: 10px;--shadow: 0 1px 4px rgba(0,0,0,.1)}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;background:var(--gray-50);color:var(--gray-900);font-size:16px;line-height:1.6;-webkit-tap-highlight-color:transparent}.page{max-width:680px;margin:0 auto;padding:1rem 1rem 6rem}.center-msg{display:flex;align-items:center;justify-content:center;height:60vh;color:var(--gray-500);font-size:1.1rem}.navbar{position:sticky;top:0;z-index:100;display:flex;gap:.5rem;align-items:center;background:var(--blue);padding:.75rem 1rem}.nav-link{color:#ffffffd9;text-decoration:none;font-size:.9rem;font-weight:500;padding:.4rem .75rem;border-radius:6px;border:none;background:none;cursor:pointer}.nav-link:hover,.nav-link.active{background:#ffffff26;color:#fff}.logout{margin-left:auto}.btn-primary,.btn-secondary{display:inline-flex;align-items:center;gap:.4rem;padding:.7rem 1.25rem;border-radius:var(--radius);font-size:.95rem;font-weight:600;cursor:pointer;border:2px solid transparent;transition:all .15s}.btn-primary{background:var(--blue);color:#fff}.btn-primary:hover:not(:disabled){background:var(--blue-dk)}.btn-primary:disabled{opacity:.5;cursor:not-allowed}.btn-secondary{background:#fff;color:var(--blue);border-color:var(--blue)}.btn-secondary:hover{background:var(--gray-100)}.btn-back{background:none;border:none;color:var(--blue);cursor:pointer;font-size:.9rem}.btn-close{background:none;border:none;font-size:1.2rem;cursor:pointer;color:var(--gray-500)}.login-wrap{display:flex;align-items:center;justify-content:center;min-height:100vh;background:linear-gradient(135deg,#eff6ff,#dbeafe)}.login-card{background:#fff;padding:2rem;border-radius:16px;box-shadow:0 4px 24px #0000001a;width:100%;max-width:380px}.logo{font-size:1.5rem;font-weight:700;color:var(--blue);margin-bottom:.25rem}.tagline{color:var(--gray-500);font-size:.9rem;margin-bottom:1.5rem}label{display:flex;flex-direction:column;gap:.35rem;font-size:.9rem;font-weight:500;margin-bottom:1rem}input[type=email],input[type=password]{padding:.65rem .9rem;border:1.5px solid var(--gray-300);border-radius:8px;font-size:1rem;outline:none;transition:border .15s}input:focus{border-color:var(--blue)}.error{color:var(--red);font-size:.9rem;margin:.5rem 0}.muted{color:var(--gray-500);font-size:.9rem}.course-list{display:flex;flex-direction:column;gap:1rem;margin-top:1rem}.course-card{background:#fff;border-radius:var(--radius);box-shadow:var(--shadow);padding:1rem 1.25rem}.course-card h2{font-size:1.05rem;margin-bottom:.5rem}.lesson-list{display:flex;flex-direction:column;gap:.25rem;margin-top:.5rem}.lesson-row{display:flex;align-items:center;gap:.75rem;padding:.6rem .75rem;border-radius:8px;text-decoration:none;color:var(--gray-900);transition:background .15s}.lesson-row:hover{background:var(--gray-100)}.lesson-row.flagged{border-left:3px solid var(--amber)}.lesson-index{width:1.6rem;height:1.6rem;border-radius:50%;background:var(--gray-100);color:var(--gray-700);display:flex;align-items:center;justify-content:center;font-size:.78rem;font-weight:600;flex-shrink:0}.lesson-title{flex:1;font-size:.93rem}.badge{padding:.2rem .5rem;border-radius:4px;font-size:.75rem;font-weight:600}.badge-ok,.badge-ok.badge{background:#dcfce7;color:var(--green)}.badge-wrong{background:#fee2e2;color:var(--red)}.badge-warn{background:#fef3c7;color:var(--amber)}.badge-review{background:#fef3c7;color:var(--amber);padding:.15rem .4rem;border-radius:4px;font-size:.75rem}.badge-pending{color:var(--gray-300)}.lesson-page h1{font-size:1.3rem;margin:1rem 0}.lesson-header{display:flex;align-items:center;gap:1rem;margin-bottom:.5rem}.course-name{color:var(--gray-500);font-size:.9rem}.banner-warning{background:#fef3c7;border:1px solid #fcd34d;color:#92400e;padding:.75rem 1rem;border-radius:8px;font-size:.9rem;margin-bottom:1rem}.lesson-content{background:#fff;border-radius:var(--radius);padding:1.25rem;box-shadow:var(--shadow);margin-bottom:1.25rem;line-height:1.7}.lesson-content h2{font-size:1.05rem;margin:1rem 0 .5rem}.lesson-content h3{font-size:.95rem;margin:.75rem 0 .35rem}.lesson-content ul,.lesson-content ol{padding-left:1.4rem}.lesson-content li{margin-bottom:.3rem}.lesson-content table{border-collapse:collapse;width:100%;font-size:.85rem}.lesson-content th,.lesson-content td{border:1px solid var(--gray-300);padding:.4rem .6rem}.lesson-actions{display:flex;gap:.75rem;flex-wrap:wrap}.quiz-page{padding-top:.5rem}.offline-bar{background:var(--gray-900);color:#fff;text-align:center;padding:.5rem;font-size:.85rem;margin:-.5rem -1rem 1rem}.quiz-progress{height:4px;background:var(--gray-100);border-radius:2px;margin-bottom:.5rem}.quiz-progress-bar{height:100%;background:var(--blue);border-radius:2px;transition:width .3s}.quiz-counter{font-size:.85rem;color:var(--gray-500);text-align:center;margin-bottom:1rem}.question-card{background:#fff;border-radius:var(--radius);padding:1.25rem;box-shadow:var(--shadow)}.question-stem{font-size:1rem;font-weight:600;margin-bottom:1rem;line-height:1.5}.options{display:flex;flex-direction:column;gap:.5rem}.option-btn{display:flex;align-items:flex-start;gap:.75rem;padding:.75rem 1rem;border:2px solid var(--gray-300);border-radius:8px;background:#fff;cursor:pointer;text-align:left;font-size:.93rem;transition:all .15s}.option-btn:hover{border-color:var(--blue);background:#eff6ff}.option-btn.selected{border-color:var(--blue);background:#dbeafe;color:var(--blue-dk)}.option-label{width:1.5rem;height:1.5rem;border-radius:50%;background:var(--gray-100);display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.8rem;flex-shrink:0}.option-btn.selected .option-label{background:var(--blue);color:#fff}.quiz-nav{display:flex;justify-content:space-between;margin:1rem 0}.dots{display:flex;gap:.4rem;justify-content:center;margin-top:.5rem}.dot{width:8px;height:8px;border-radius:50%;background:var(--gray-300);cursor:pointer}.dot.active{background:var(--blue)}.dot.done{background:var(--blue-dk)}.results-page{text-align:center}.score-section{padding:2rem 0 1rem}.score-circle{width:100px;height:100px;border-radius:50%;border:6px solid;display:flex;align-items:center;justify-content:center;font-size:1.5rem;font-weight:700;margin:0 auto 1rem}.score-circle.offline{border-color:var(--gray-300);color:var(--gray-500);font-size:2rem}.result-offline{padding:2rem 0}.sync-msg{color:var(--green);margin:.5rem 0;font-size:.9rem}.answers-review{text-align:left;margin-top:1.5rem}.answers-review h3{margin-bottom:.75rem}.answer-row{background:#fff;border-radius:8px;padding:1rem;margin-bottom:.75rem;box-shadow:var(--shadow)}.answer-row.correct{border-left:4px solid var(--green)}.answer-row.wrong{border-left:4px solid var(--red)}.answer-head{display:flex;align-items:center;gap:.5rem;margin-bottom:.4rem}.q-num{font-weight:700;color:var(--gray-700)}.correct-answer{font-size:.9rem;color:var(--green);margin:.3rem 0}.explanation{font-size:.88rem;color:var(--gray-700);margin:.3rem 0}.source-ref{font-size:.8rem;color:var(--gray-500);margin-top:.3rem}.results-actions{display:flex;gap:.75rem;justify-content:center;margin-top:1.5rem;flex-wrap:wrap}.progress-row{display:flex;align-items:center;justify-content:space-between;padding:.6rem .5rem;border-bottom:1px solid var(--gray-100)}.progress-info{display:flex;align-items:center;gap:.75rem;flex:1;min-width:0}.progress-meta{display:flex;align-items:center;gap:.5rem;flex-shrink:0}.source-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#0006;z-index:200;display:flex;align-items:flex-end}.source-drawer{background:#fff;width:100%;max-height:75vh;border-radius:16px 16px 0 0;padding:1.25rem;overflow-y:auto}.drawer-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:1rem}.drawer-header h3{font-size:1rem}.source-chunk{border:1px solid var(--gray-100);border-radius:8px;padding:.75rem;margin-bottom:.75rem}.chunk-meta{display:flex;gap:.5rem;margin-bottom:.4rem}.chunk-tag{background:var(--gray-100);color:var(--gray-700);padding:.1rem .4rem;border-radius:4px;font-size:.75rem;font-weight:600}.chunk-idx{color:var(--gray-500);font-size:.75rem}.chunk-text{font-size:.88rem;line-height:1.55;color:var(--gray-700)}
