/* ===== KHU HỌC TẬP (giáo viên · học sinh · phụ huynh) ===== */
#learn-zone{position:fixed;inset:0;z-index:1500;background:#f1f5f9;overflow-y:auto;display:none;font-size:14.5px;color:#0f172a}
#learn-zone.open{display:block}
body.lz-lock{overflow:hidden}
.lz-top{position:sticky;top:0;z-index:5;background:linear-gradient(90deg,#0f172a,#1e3a8a);color:#fff;box-shadow:0 2px 12px rgba(0,0,0,.2)}
.lz-top-in{max-width:1240px;margin:0 auto;display:flex;align-items:center;gap:10px;padding:10px 16px;flex-wrap:wrap}
.lz-brand{font-weight:800;font-size:18px;display:flex;align-items:center;gap:8px;white-space:nowrap}
.lz-brand small{font-weight:600;font-size:12px;background:rgba(255,255,255,.15);padding:2px 8px;border-radius:999px}
.lz-tabs{display:flex;gap:4px;flex-wrap:wrap;margin-left:12px}
.lz-tab{background:none;border:none;color:#cbd5e1;font-weight:700;padding:8px 12px;border-radius:8px;cursor:pointer;font-size:14px;white-space:nowrap}
.lz-tab:hover{background:rgba(255,255,255,.1);color:#fff}
.lz-tab.on{background:#fff;color:#1e3a8a}
.lz-right{margin-left:auto;display:flex;align-items:center;gap:8px}
.lz-iconbtn{position:relative;background:rgba(255,255,255,.12);border:none;color:#fff;width:38px;height:38px;border-radius:50%;cursor:pointer;font-size:15px}
.lz-iconbtn .lz-badge{position:absolute;top:-4px;right:-4px;background:#ef4444;color:#fff;font-size:10.5px;font-weight:800;min-width:18px;height:18px;border-radius:9px;display:flex;align-items:center;justify-content:center;padding:0 4px}
.lz-back{background:#f59e0b;color:#0f172a;border:none;font-weight:800;padding:8px 14px;border-radius:999px;cursor:pointer;white-space:nowrap}
.lz-main{max-width:1240px;margin:0 auto;padding:18px 16px 60px}
.lz-h1{font-size:22px;font-weight:800;margin:4px 0 14px;display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.lz-h2{font-size:16px;font-weight:800;margin:18px 0 10px;display:flex;align-items:center;gap:8px}
.lz-sub{color:#64748b;font-size:13px;font-weight:500}
.lz-card{background:#fff;border:1px solid #e2e8f0;border-radius:14px;padding:16px;box-shadow:0 1px 3px rgba(15,23,42,.04)}
.lz-grid{display:grid;gap:14px;grid-template-columns:repeat(auto-fill,minmax(260px,1fr))}
.lz-stats{display:grid;gap:12px;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));margin-bottom:6px}
.lz-stat{background:#fff;border:1px solid #e2e8f0;border-radius:14px;padding:14px 16px}
.lz-stat b{display:block;font-size:26px;font-weight:800;color:#1e3a8a;line-height:1.1}
.lz-stat span{color:#64748b;font-size:12.5px;font-weight:600}
.lz-class{cursor:pointer;transition:transform .15s,box-shadow .15s;border-top:4px solid #2563eb}
.lz-class:hover{transform:translateY(-2px);box-shadow:0 8px 24px rgba(15,23,42,.1)}
.lz-class h3{margin:0 0 4px;font-size:16px}
.lz-chip{display:inline-flex;align-items:center;gap:4px;background:#eff6ff;color:#1d4ed8;font-size:12px;font-weight:700;padding:3px 9px;border-radius:999px;margin:2px 4px 2px 0}
.lz-chip.g{background:#ecfdf5;color:#047857}.lz-chip.o{background:#fff7ed;color:#c2410c}.lz-chip.p{background:#f5f3ff;color:#6d28d9}
.lz-btn{display:inline-flex;align-items:center;gap:6px;background:#2563eb;color:#fff;border:none;font-weight:700;padding:9px 14px;border-radius:10px;cursor:pointer;font-size:14px}
.lz-btn:hover{background:#1d4ed8}.lz-btn.ghost{background:#fff;color:#1e3a8a;border:1px solid #cbd5e1}.lz-btn.ghost:hover{background:#f8fafc}
.lz-btn.red{background:#fee2e2;color:#b91c1c}.lz-btn.sm{padding:6px 10px;font-size:12.5px;border-radius:8px}
.lz-btn:disabled{opacity:.6;cursor:not-allowed}
.lz-input,.lz-textarea,.lz-select{width:100%;border:1px solid #cbd5e1;border-radius:10px;padding:10px 12px;font-size:14px;font-family:inherit;background:#fff;box-sizing:border-box}
.lz-textarea{min-height:90px;resize:vertical}
.lz-row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.lz-row>*{flex:1 1 180px}
.lz-form label{display:block;font-weight:700;font-size:13px;margin:10px 0 4px}
.lz-roles{display:grid;gap:14px;grid-template-columns:repeat(auto-fit,minmax(230px,1fr))}
.lz-role{cursor:pointer;text-align:center;border:2px solid #e2e8f0;padding:22px 16px}
.lz-role:hover,.lz-role.on{border-color:#2563eb;background:#eff6ff}
.lz-role .ic{font-size:40px}
.lz-role h3{margin:8px 0 6px}
.lz-role p{color:#475569;font-size:13px;margin:0}
.lz-hero{background:linear-gradient(135deg,#1e3a8a,#7c3aed);color:#fff;border-radius:18px;padding:26px 22px;margin-bottom:16px}
.lz-hero h2{margin:0 0 6px;font-size:24px}
.lz-hero p{margin:0;opacity:.92}
.lz-feat{display:grid;gap:12px;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));margin-top:14px}
.lz-feat div{background:rgba(255,255,255,.12);border-radius:12px;padding:12px;font-size:13.5px}
.lz-code{font-family:ui-monospace,Menlo,Consolas,monospace;font-size:20px;font-weight:800;letter-spacing:2px;background:#0f172a;color:#facc15;padding:6px 14px;border-radius:10px;display:inline-block}
.lz-table{width:100%;border-collapse:collapse;font-size:13.5px}
.lz-table th,.lz-table td{padding:9px 8px;border-bottom:1px solid #e2e8f0;text-align:left;vertical-align:top}
.lz-table th{background:#f8fafc;font-size:12.5px;color:#475569}
.lz-scroll{overflow-x:auto}
.lz-post{border-left:4px solid #2563eb;margin-bottom:10px}
.lz-post .meta{color:#64748b;font-size:12px;margin-bottom:6px}
.lz-post .body{white-space:pre-wrap;line-height:1.55}
.lz-subtabs{display:flex;gap:6px;flex-wrap:wrap;margin:6px 0 14px;border-bottom:1px solid #e2e8f0;padding-bottom:8px}
.lz-subtab{background:none;border:none;font-weight:700;color:#475569;padding:7px 12px;border-radius:8px;cursor:pointer}
.lz-subtab.on{background:#1e3a8a;color:#fff}
.lz-threads{display:grid;grid-template-columns:320px 1fr;gap:14px;min-height:60vh}
.lz-tlist{max-height:70vh;overflow-y:auto;padding:6px}
.lz-titem{padding:10px;border-radius:10px;cursor:pointer;border-bottom:1px solid #f1f5f9}
.lz-titem:hover,.lz-titem.on{background:#eff6ff}
.lz-titem b{display:block;font-size:14px}
.lz-titem small{color:#64748b;display:block;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.lz-chat{display:flex;flex-direction:column;max-height:70vh}
.lz-msgs{flex:1;overflow-y:auto;padding:6px 4px;display:flex;flex-direction:column;gap:8px;min-height:240px}
.lz-msg{max-width:78%;background:#f1f5f9;border-radius:14px;padding:8px 12px;align-self:flex-start}
.lz-msg.me{align-self:flex-end;background:#dbeafe}
.lz-msg .who{font-size:11.5px;font-weight:800;color:#475569;margin-bottom:2px}
.lz-msg .txt{white-space:pre-wrap;line-height:1.5}
.lz-msg .at{font-size:10.5px;color:#94a3b8;margin-top:2px;text-align:right}
.lz-send{display:flex;gap:8px;margin-top:8px}
.lz-send textarea{flex:1;min-height:46px}
.lz-empty{color:#64748b;text-align:center;padding:26px 10px}
.lz-notif{padding:10px 12px;border-radius:10px;cursor:pointer;border-bottom:1px solid #f1f5f9}
.lz-notif.unread{background:#eff6ff}
.lz-notif b{display:block}
.lz-notif small{color:#64748b}
.lz-soon{border:1px dashed #94a3b8;background:#f8fafc}
.lz-soon h4{margin:0 0 4px}
.lz-dlg{position:fixed;inset:0;background:rgba(15,23,42,.55);z-index:1600;display:flex;align-items:center;justify-content:center;padding:16px}
.lz-dlg .lz-card{width:min(560px,100%);max-height:90vh;overflow-y:auto}
.lz-toast{position:fixed;left:50%;bottom:26px;transform:translateX(-50%);background:#0f172a;color:#fff;padding:10px 18px;border-radius:999px;z-index:1700;font-weight:700;box-shadow:0 8px 24px rgba(0,0,0,.3)}
@media (max-width:820px){
  .lz-hide-sm{display:none}
  .lz-threads{grid-template-columns:1fr}
  .lz-tabs{margin-left:0;order:3;width:100%}
  .lz-brand{font-size:16px}
  .lz-msg{max-width:92%}
}
@media print{
  body *{visibility:hidden}
  #lz-print,#lz-print *{visibility:visible}
  #lz-print{position:absolute;left:0;top:0;width:100%}
}
/* ===== Giai đoạn 4: lớp online · thí nghiệm ảo · nội dung · Hub · gói ===== */
.lz-dlg.wide .lz-card{width:min(860px,100%)}
.lz-dlg.full{padding:8px}
.lz-dlg.full .lz-card{width:min(1280px,100%);height:94vh;max-height:94vh;display:flex;flex-direction:column;padding:10px;overflow:hidden}
.lz-dlg.full iframe{flex:1;width:100%;border:0;border-radius:10px;background:#f8fafc}
.lz-bar{display:flex;gap:10px;align-items:center;flex-wrap:wrap;border-radius:12px;padding:10px 14px;margin:0 0 12px;font-weight:600;font-size:14px;background:#eff6ff;color:#1e3a8a;border:1px solid #bfdbfe}
.lz-bar.warn{background:#fff7ed;color:#9a3412;border-color:#fed7aa}.lz-bar.bad{background:#fef2f2;color:#991b1b;border-color:#fecaca}.lz-bar.ok{background:#ecfdf5;color:#065f46;border-color:#a7f3d0}
.lz-bar .lz-btn{margin-left:auto}
.lz-sess{display:flex;gap:12px;align-items:center;flex-wrap:wrap;padding:10px 0;border-bottom:1px solid #f1f5f9}
.lz-sess:last-child{border-bottom:0}
.lz-sess .when{min-width:92px;text-align:center;background:#f1f5f9;border-radius:10px;padding:6px 8px;font-weight:800;color:#1e3a8a;line-height:1.2}
.lz-sess .when small{display:block;font-weight:600;color:#64748b;font-size:11.5px}
.lz-sess .info{flex:1 1 220px;min-width:0}
.lz-live{background:#dc2626;color:#fff;font-size:11px;font-weight:800;padding:2px 8px;border-radius:999px;animation:lzpulse 1.4s infinite}
@keyframes lzpulse{50%{opacity:.55}}
.lz-lab{display:flex;flex-direction:column;gap:6px}
.lz-lab .ic{font-size:28px}
.lz-lab h4{margin:0;font-size:15px}
.lz-lab .acts{margin-top:auto;display:flex;gap:6px;flex-wrap:wrap}
.lz-agent{display:flex;flex-direction:column;gap:6px}
.lz-agent h4{margin:0;font-size:15px;display:flex;gap:8px;align-items:center}
.lz-agent .num{font-size:22px;font-weight:800;color:#1e3a8a}
.lz-dot{width:9px;height:9px;border-radius:50%;display:inline-block;background:#10b981}.lz-dot.off{background:#94a3b8}
.lz-plan{text-align:center;display:flex;flex-direction:column;gap:6px}
.lz-plan .price{font-size:26px;font-weight:800;color:#b45309}
.lz-plan.hot{border:2px solid #2563eb}
.lz-post-txt{white-space:pre-wrap;font-size:14px;line-height:1.55}