:root{--bg: #f6f8fb;--card: #ffffff;--text: #1a2332;--muted: #5c6b7f;--primary: #3b6ff5;--primary-soft: #e8efff;--border: #e2e8f0;--success: #16a34a;--danger: #dc2626;--radius: 14px;--shadow: 0 8px 30px rgba(26, 35, 50, .06)}*{box-sizing:border-box}body{margin:0;font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--text);line-height:1.5}a{color:var(--primary);text-decoration:none}.container{width:min(1100px,92vw);margin:0 auto;padding:24px 0 48px}.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:20px}.grid{display:grid;gap:16px}.grid-2{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}.topbar{background:var(--card);border-bottom:1px solid var(--border);padding:14px 0;position:sticky;top:0;z-index:10}.topbar-inner{width:min(1100px,92vw);margin:0 auto;display:flex;align-items:center;justify-content:space-between;gap:12px}.brand{font-weight:700;font-size:1.05rem}.nav-links{display:flex;gap:12px;flex-wrap:wrap;align-items:center}.nav-links a{color:var(--muted);font-weight:600;padding:6px 10px;border-radius:8px}.nav-links a.nav-active,.nav-links a:hover{color:var(--primary);background:var(--primary-soft)}.btn{border:none;border-radius:10px;padding:10px 16px;font-weight:600;cursor:pointer;background:var(--primary);color:#fff}.btn.secondary{background:var(--primary-soft);color:var(--primary)}.btn.ghost{background:transparent;color:var(--muted);border:1px solid var(--border)}.input,.select,.textarea{width:100%;border:1px solid var(--border);border-radius:10px;padding:10px 12px;font:inherit;background:#fff}.label{display:block;margin-bottom:6px;font-size:.9rem;color:var(--muted)}.muted{color:var(--muted)}.badge{display:inline-block;padding:4px 10px;border-radius:999px;background:var(--primary-soft);color:var(--primary);font-size:.8rem;font-weight:600}.chat-layout{display:grid;grid-template-columns:1fr;gap:16px}@media(min-width:900px){.chat-layout{grid-template-columns:280px 1fr}}.chat-messages{min-height:420px;max-height:60vh;overflow-y:auto;overflow-x:hidden;display:flex;flex-direction:column;gap:12px;padding-right:4px;overscroll-behavior:contain}.lesson-group{border:1px solid var(--border);border-radius:12px;background:#fff;flex-shrink:0}.lesson-group-header{width:100%;display:flex;flex-wrap:wrap;align-items:center;gap:8px 12px;padding:12px 14px;border:none;background:#f8fafc;cursor:pointer;text-align:left;font:inherit;color:inherit}.lesson-group-header:hover{background:#f1f5f9}.lesson-group-chevron{flex:0 0 auto;font-size:.75rem;color:var(--muted, #64748b)}.lesson-group-title{flex:1 1 auto;font-weight:600;min-width:0}.lesson-group-badge{flex:0 0 auto;padding:2px 8px;border-radius:999px;background:var(--primary-soft);color:var(--primary);font-size:.75rem;font-weight:600}.lesson-group-meta{flex:1 1 100%;display:flex;gap:12px;font-size:.8rem;color:var(--muted, #64748b);padding-left:1.25rem}.lesson-group-body{display:flex;flex-direction:column;gap:12px;padding:12px 14px;border-top:1px solid var(--border);max-height:min(52vh,520px);overflow-y:auto;overflow-x:hidden;overscroll-behavior:contain;-webkit-overflow-scrolling:touch}.lesson-group.collapsed .lesson-group-body{display:none}.msg{max-width:85%;padding:12px 14px;border-radius:12px;white-space:pre-wrap}.msg.user{align-self:flex-end;background:var(--primary);color:#fff}.msg.assistant{align-self:flex-start;background:#f1f5f9;border:1px solid var(--border)}.msg.thinking{align-self:flex-start;background:#fff7ed;border:1px dashed #fdba74;color:#9a3412;font-size:.9rem}.chat-input-row{display:flex;gap:10px;margin-top:12px}.chat-input-row .textarea{min-height:48px;resize:vertical}.stat-value{font-size:1.6rem;font-weight:700}.stat-link{border:none;background:none;padding:0;margin:0;font:inherit;font-size:inherit;font-weight:inherit;color:var(--primary);cursor:pointer;text-decoration:underline;text-underline-offset:3px}.stat-link:hover{color:#2952c4}.modal-overlay{position:fixed;top:0;right:0;bottom:0;left:0;z-index:1000;background:#0f172a73;display:flex;align-items:center;justify-content:center;padding:20px}.modal-card{width:min(720px,100%);max-height:min(80vh,720px);overflow:hidden;display:flex;flex-direction:column;background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);border:1px solid var(--border)}.modal-header{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:16px 20px;border-bottom:1px solid var(--border)}.modal-body{overflow-y:auto;padding:16px 20px 20px;display:flex;flex-direction:column;gap:12px}.question-detail-item{border:1px solid var(--border);border-radius:12px;padding:12px 14px;display:flex;flex-direction:column;gap:6px}.question-detail-meta{display:flex;flex-wrap:wrap;gap:8px;font-size:.8rem;color:var(--muted)}.badge-grade-unanswered{background:#fef3c7;color:#92400e}.badge-grade-wrong{background:#fee2e2;color:#b91c1c}.badge-grade-partial{background:#ffedd5;color:#c2410c}.badge-grade-correct{background:#dcfce7;color:#166534}.tabs{display:flex;gap:8px;margin-bottom:16px}.tab{padding:8px 14px;border-radius:999px;border:1px solid var(--border);background:#fff;cursor:pointer}.tab.active{background:var(--primary);color:#fff;border-color:var(--primary)}.error{color:var(--danger);margin-top:8px}.course-table{display:flex;flex-direction:column;gap:4px}.course-row{display:grid;grid-template-columns:1fr 72px 130px 72px;gap:10px;align-items:center;padding:10px 12px;border-radius:10px;border:1px solid var(--border);font-size:.92rem}.course-head{background:#f8fafc;font-weight:600;color:var(--muted);border-style:dashed}.course-row-completed{background:#f0fdf4;border-color:#bbf7d0}.course-row-planned{background:var(--primary-soft)}.course-row-lab{opacity:.92}.course-topic{display:flex;flex-wrap:wrap;gap:6px;align-items:center}.badge{display:inline-block;padding:2px 8px;border-radius:999px;font-size:.75rem;font-weight:600;white-space:nowrap}.badge-completed{background:#dcfce7;color:#166534}.badge-planned{background:#dbeafe;color:#1d4ed8}.badge-upcoming{background:#f1f5f9;color:var(--muted)}.badge-repeat{background:#fef3c7;color:#92400e}.badge-lab{background:#ede9fe;color:#5b21b6}.course-repeat-item{display:flex;flex-wrap:wrap;gap:8px;align-items:baseline;padding:10px 0;border-bottom:1px solid var(--border)}.course-repeat-item:last-child{border-bottom:none}@media(max-width:720px){.course-row{grid-template-columns:1fr;gap:4px}.course-head{display:none}}.admin-shell{display:grid;grid-template-columns:240px 1fr;gap:20px;min-height:calc(100vh - 120px)}.admin-sidebar{position:sticky;top:16px;align-self:start;padding:16px;display:flex;flex-direction:column;gap:12px}.admin-brand{font-weight:800;font-size:1.1rem;color:var(--primary)}.admin-nav{display:flex;flex-direction:column;gap:4px}.admin-nav-link{padding:10px 12px;border-radius:10px;color:inherit;text-decoration:none}.admin-nav-link:hover{background:var(--primary-soft)}.admin-nav-link.active{background:var(--primary-soft);color:var(--primary);font-weight:600}.admin-sidebar-foot{margin-top:auto;display:flex;flex-direction:column;gap:8px;padding-top:12px;border-top:1px solid var(--border)}.admin-main h1{margin-top:0}.admin-stat-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:12px;margin-bottom:20px}.admin-stat{padding:16px}.admin-stat-value{font-size:1.5rem;font-weight:800}.admin-stat-label{font-size:.85rem;color:var(--muted);margin-top:4px}.admin-stat-hint{font-size:.75rem;margin-top:4px}.admin-table-wrap{overflow-x:auto;padding:12px}.admin-table{width:100%;border-collapse:collapse;font-size:.9rem}.admin-table th,.admin-table td{padding:10px 8px;border-bottom:1px solid var(--border);text-align:left;vertical-align:top}.admin-table th{font-size:.8rem;color:var(--muted);font-weight:600}.admin-subrow td{background:#f8fafc;font-size:.85rem}.admin-actions{white-space:nowrap}.admin-form-row{padding:16px}.admin-form-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:12px;margin:12px 0}.btn-link{border:none;background:none;padding:0;font:inherit;color:var(--primary);cursor:pointer;text-align:left}.btn.small,.btn.ghost.small{padding:4px 8px;font-size:.8rem;min-height:auto}.badge.danger{background:#fef2f2;color:#b91c1c}.badge.ok{background:#ecfdf5;color:#047857}.badge.muted{background:#f1f5f9;color:#64748b}.admin-table .pos{color:#047857;font-weight:600}.admin-table .neg{color:#b91c1c;font-weight:600}.admin-details code{font-size:.75rem;word-break:break-all}.admin-quick-links ul{margin:0;padding-left:20px}.admin-filters{padding:12px;margin-bottom:8px}.admin-groups .admin-group{margin-bottom:8px;padding:8px 12px}.admin-groups summary{cursor:pointer;font-weight:600;padding:6px 0}@media(max-width:900px){.admin-shell{grid-template-columns:1fr}.admin-sidebar{position:static}.admin-nav{flex-direction:row;flex-wrap:wrap}}