/* ============================================================
   MÖBIUS — lớp giao diện mới (nạp SAU app.css)
   app.css vẫn phục vụ các màn soạn đề / chơi live / báo cáo bảng.
   Mọi class mới đều có tiền tố mb- để không đụng class cũ.
   ============================================================ */
@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:wght@400;500;600;700;800&display=swap');

:root{
  --mb-bg:#0a1611; --mb-side:#0c1b14;
  --mb-panel:#10231a; --mb-panel2:#142b20; --mb-panel3:#183526;
  --mb-line:#20402f; --mb-line-soft:#1a3325;
  --mb-gold:#e6c56f; --mb-gold2:#c79a3a; --mb-gold-dark:#8a6a1f;
  --mb-text:#f1ebda; --mb-muted:#a8c4b4; --mb-dim:#789684; --mb-mint:#7fe8c7;
  --mb-green:#3ecb77; --mb-red:#e07a6a;
}
body{
  font-family:'Be Vietnam Pro','Segoe UI','Helvetica Neue',Arial,sans-serif;
  background:radial-gradient(1200px 700px at 75% -10%, #123023 0%, var(--mb-bg) 60%);
  background-attachment:fixed;
  color:var(--mb-text);
}
body.has-theme{
  background-size:cover;
  background-position:center;
  background-repeat:no-repeat;
}
@media (max-width:640px) and (orientation:portrait){
  body.has-theme{
    background-image:
      linear-gradient(rgba(8,20,14,.72), rgba(8,20,14,.84)),
      var(--theme-image),
      var(--theme-image) !important;
    background-size:cover, contain, cover !important;
    background-position:center, center top, center !important;
    background-repeat:no-repeat, no-repeat, no-repeat !important;
    background-attachment:scroll, scroll, scroll !important;
  }
}

/* ===== Khung 2 cột của trang giáo viên ===== */
.mb-shell{display:flex;min-height:100vh}
.mb-side{
  width:244px;flex-shrink:0;
  background:linear-gradient(180deg,var(--mb-side),#0a1812);
  border-right:1px solid var(--mb-line-soft);
  padding:18px 14px 14px;
  display:flex;flex-direction:column;gap:6px;
  position:sticky;top:0;height:100vh;overflow-y:auto;
}
.mb-main{flex:1;min-width:0;display:flex;flex-direction:column}
.mb-main .wrap{max-width:1080px;width:100%;min-height:100vh;padding-top:26px;display:flex;flex-direction:column}
/* Chế độ tập trung: soạn đề / tổ chức chơi / đăng nhập — ẩn sidebar */
body.mb-focus .mb-side{display:none}
body.mb-focus .mb-main .wrap{max-width:960px;margin:0 auto}

/* ===== Thương hiệu ===== */
.mb-brand{text-align:center;padding:0 4px 8px}
.mb-brand[role=button]{cursor:pointer;border-radius:14px}
.mb-brand[role=button]:hover{background:rgba(230,197,111,.06)}
.mb-brand[role=button]:focus-visible,.mb-home-link:focus-visible{outline:2px solid var(--mb-gold);outline-offset:4px}
.mb-brand img{width:112px;display:block;margin:0 auto 3px;filter:drop-shadow(0 6px 14px rgba(0,0,0,.45))}
.mb-brand .name{
  font-weight:800;font-size:15px;letter-spacing:.32em;margin-left:.32em;display:block;
  background:linear-gradient(100deg,#f4dfa0,var(--mb-gold) 45%,#a37c25);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.mb-brand .slogan{font-size:10px;color:var(--mb-dim);margin-top:3px}
.mb-brand-inline{display:flex;align-items:center;gap:9px;justify-content:center;margin:6px 0 14px}
.mb-home-link{
  width:max-content;margin-left:auto;margin-right:auto;padding:4px 10px;border:0;border-radius:14px;
  background:transparent;color:inherit;cursor:pointer;font-family:inherit;
}
.mb-home-link:hover{background:rgba(230,197,111,.08)}
.mb-brand-inline img{width:46px;filter:drop-shadow(0 3px 8px rgba(0,0,0,.4))}
.mb-brand-inline .name{
  font-weight:800;font-size:17px;letter-spacing:.3em;
  background:linear-gradient(100deg,#f4dfa0,var(--mb-gold) 45%,#a37c25);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}

/* ===== Sidebar ===== */
.mb-create{
  display:flex;align-items:center;justify-content:center;gap:8px;
  background:linear-gradient(135deg,#f0d489,var(--mb-gold2));
  color:#241a05;font-weight:800;font-size:15px;border:none;cursor:pointer;
  padding:11px 12px;border-radius:12px;margin-bottom:6px;font-family:inherit;
  box-shadow:0 6px 18px rgba(199,154,58,.28);transition:transform .12s;
}
.mb-create:hover{transform:translateY(-1px)}
.mb-pdf-create{
  margin-bottom:8px;background:rgba(230,197,111,.08);color:#f2d486;
  border:1px solid rgba(230,197,111,.34);box-shadow:none;
}
.mb-pdf-create:hover{border-color:rgba(230,197,111,.55);background:rgba(230,197,111,.12)}
.mb-pdf-create.locked{
  background:var(--mb-panel);color:var(--mb-dim);border:1px solid var(--mb-line-soft);
  box-shadow:none;
}
.mb-pdf-create.locked:hover{transform:none;color:var(--mb-muted)}
.mb-upgrade-create{
  background:linear-gradient(135deg,#8ef0bf,#1aa36f);
  color:#062216;
  box-shadow:0 6px 18px rgba(62,203,119,.18);
}
.mb-upgrade-create.paid{
  background:var(--mb-panel);
  color:var(--mb-gold);
  border:1px solid rgba(230,197,111,.24);
  box-shadow:none;
}
.mb-admin-create{
  background:var(--mb-panel);
  color:#cdeada;
  border:1px solid var(--mb-line);
  box-shadow:none;
}
.mb-nav{
  display:flex;align-items:center;gap:12px;width:100%;border:1px solid transparent;
  min-height:50px;padding:9px 12px;border-radius:14px;cursor:pointer;background:none;font-family:inherit;
  color:var(--mb-muted);font-size:15px;font-weight:700;line-height:1.2;text-align:left;transition:background .12s,color .12s,border-color .12s;
}
.mb-nav .ic{width:32px;height:32px;flex-shrink:0;font-size:0;display:flex;align-items:center;justify-content:center}
.mb-nav .ic svg{width:30px;height:30px;display:block;filter:drop-shadow(0 5px 12px rgba(0,0,0,.28))}
.mb-nav:hover{background:var(--mb-panel);color:var(--mb-text)}
.mb-nav.on{
  background:linear-gradient(90deg,rgba(28,67,47,.88),rgba(20,43,32,.72));
  color:var(--mb-gold);font-weight:800;border-color:rgba(230,197,111,.2);
  box-shadow:inset 4px 0 0 var(--mb-gold),0 8px 20px rgba(0,0,0,.16);
}
.mb-donate{
  margin-top:auto;background:var(--mb-panel);border:1px solid var(--mb-line-soft);
  border-radius:14px;padding:16px 14px;text-align:center;
}
.mb-donate img{width:104px;border-radius:10px;display:block;margin:0 auto 8px;background:#e9e2cf;padding:4px}
.mb-donate h4{font-size:13.5px;font-weight:700;color:var(--mb-gold);margin:0 0 4px}
.mb-donate p{font-size:11px;color:var(--mb-dim);line-height:1.5;margin:0}
.mb-user{
  display:flex;align-items:center;gap:9px;margin-top:10px;
  background:var(--mb-panel);border:1px solid var(--mb-line-soft);
  border-radius:12px;padding:8px 10px;font-size:12.5px;
}
.mb-user .who{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-weight:600}
.mb-pro-badge{
  flex-shrink:0;display:inline-flex;align-items:center;gap:3px;
  border:1px solid rgba(230,197,111,.38);border-radius:999px;
  background:rgba(230,197,111,.12);color:var(--mb-gold);
  padding:2px 7px;font-size:10.5px;font-weight:800;line-height:1.2;
}
.mb-pro-badge span{font-size:12px;line-height:1}
.mb-user button{background:none;border:none;color:var(--mb-dim);cursor:pointer;font-size:12.5px;font-family:inherit;padding:2px 4px}
.mb-user button:hover{color:var(--mb-red)}
.mb-upgrade-ad{
  width:100%;display:flex;flex-direction:column;gap:5px;margin-top:6px;
  border:1px solid rgba(230,197,111,.28);border-radius:14px;
  background:linear-gradient(150deg,rgba(24,53,38,.92),rgba(13,31,22,.96));
  color:var(--mb-text);padding:12px 13px;text-align:left;cursor:pointer;font-family:inherit;
  box-shadow:0 10px 24px rgba(0,0,0,.16),inset 0 1px 0 rgba(255,255,255,.04);
}
.mb-upgrade-ad:hover{border-color:rgba(230,197,111,.52);transform:translateY(-1px)}
.mb-upgrade-ad-top{display:flex;align-items:center;justify-content:space-between;gap:8px;font-size:10.5px;font-weight:800;color:var(--mb-muted);text-transform:uppercase;letter-spacing:.04em}
.mb-upgrade-ad-top b{color:var(--mb-gold);font-size:12px;text-transform:none;letter-spacing:0;white-space:nowrap}
.mb-upgrade-ad-title{font-size:14px;font-weight:800;color:#f5e7b7;line-height:1.2}
.mb-upgrade-ad-sub{font-size:11.5px;color:var(--mb-muted);line-height:1.35}
.mb-upgrade-ad-cta{
  margin-top:2px;display:flex;align-items:center;justify-content:center;
  border-radius:10px;background:linear-gradient(135deg,#f0d489,var(--mb-gold2));
  color:#241a05;font-weight:900;font-size:12.5px;padding:7px 10px;
}

/* ===== Đầu trang ===== */
.mb-head{display:flex;align-items:center;gap:15px;margin-bottom:18px}
.mb-head .icon svg{width:38px;height:38px}
.mb-head .icon{
  width:54px;height:54px;border-radius:14px;display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,var(--mb-panel3),var(--mb-panel));border:1px solid var(--mb-line);font-size:20px;
}
.mb-head h1{margin:0;font-size:29px;font-weight:800;letter-spacing:-.01em}
.mb-head p{margin:3px 0 0;color:var(--mb-muted);font-size:15.5px}

/* ===== Thanh công cụ ===== */
.mb-toolbar{display:flex;gap:10px;margin-bottom:16px;flex-wrap:wrap}
.mb-search{
  flex:1;min-width:180px;display:flex;align-items:center;gap:9px;
  background:var(--mb-panel);border:1px solid var(--mb-line-soft);border-radius:12px;padding:0 13px;
}
.mb-search input{
  flex:1;background:none;border:none;outline:none;color:var(--mb-text);
  padding:12px 0;font-size:15px;font-family:inherit;font-weight:600;
}
.mb-search input::placeholder{color:var(--mb-dim)}
.mb-select{
  background:var(--mb-panel);border:1px solid var(--mb-line-soft);border-radius:12px;
  color:var(--mb-text);padding:0 34px 0 14px;font-size:14.5px;height:46px;font-family:inherit;font-weight:650;
  appearance:none;outline:none;cursor:pointer;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%238fae9b' stroke-width='2' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat:no-repeat;background-position:right 12px center;
}
.mb-vtoggle{display:flex;background:var(--mb-panel);border:1px solid var(--mb-line-soft);border-radius:12px;padding:4px;height:46px}
.mb-vtoggle button{width:40px;border:none;border-radius:8px;cursor:pointer;background:none;color:var(--mb-dim);font-size:15px}
.mb-vtoggle button.on{background:linear-gradient(135deg,#f0d489,var(--mb-gold2));color:#241a05}

/* ===== Cây thư mục + vùng nội dung ===== */
.mb-ws{display:flex;gap:16px;align-items:flex-start}
.mb-tree{
  width:260px;flex-shrink:0;background:rgba(16,35,26,.62);
  border:1px solid var(--mb-line-soft);border-radius:16px;padding:12px 10px;
  max-height:calc(100vh - 210px);overflow-y:auto;
}
.mb-trow{
  display:flex;align-items:center;gap:5px;padding:8px 8px;border-radius:9px;border:1px solid transparent;
  cursor:pointer;color:var(--mb-muted);font-size:14.5px;font-weight:600;position:relative;
}
.mb-trow:hover{background:var(--mb-panel2);color:var(--mb-text)}
.mb-trow.sel{background:linear-gradient(90deg,var(--mb-panel3),var(--mb-panel2));color:var(--mb-gold);font-weight:600;border-color:var(--mb-line)}
/* Kéo-thả đề vào cây thư mục */
.mb-trow.drop-hi{
  background:rgba(230,197,111,.16);color:var(--mb-gold);
  outline:2px dashed rgba(230,197,111,.7);outline-offset:-2px;
}
body.mb-quiz-dragging .mb-tree .mb-trow{border-color:rgba(230,197,111,.28)}
.mb-card[draggable="true"],.mbr[draggable="true"]{cursor:grab}
.mb-undo-toast{
  position:fixed;left:50%;bottom:26px;transform:translateX(-50%);z-index:9999;
  display:flex;align-items:center;gap:14px;max-width:min(92vw,560px);
  padding:12px 18px;border-radius:14px;
  background:rgba(16,30,23,.96);border:1px solid rgba(230,197,111,.4);
  color:#eef2ea;font-size:14px;font-weight:650;
  box-shadow:0 10px 34px rgba(0,0,0,.45);
}
.mb-undo-toast b{color:var(--mb-gold)}
.mb-undo-toast .mb-undo-btn{
  flex-shrink:0;padding:7px 14px;border-radius:10px;cursor:pointer;
  border:1px solid rgba(230,197,111,.5);background:rgba(230,197,111,.12);
  color:var(--mb-gold);font-family:inherit;font-size:13px;font-weight:800;white-space:nowrap;
}
.mb-undo-toast .mb-undo-btn:hover{background:rgba(230,197,111,.24)}
.mb-trow .tname{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.mb-trow .tmore{
  width:24px;height:24px;border:none;border-radius:6px;color:var(--mb-dim);flex-shrink:0;cursor:pointer;
  display:flex;align-items:center;justify-content:center;font-size:14px;background:none;font-family:inherit;
  opacity:.55; /* hiện thường trực (hơi mờ) — mục tiêu cố định, không phải rê trúng hàng mới hiện */
}
.mb-trow:hover .tmore,.mb-trow.sel .tmore{opacity:1}
.mb-trow .tmore:hover{color:var(--mb-gold);background:var(--mb-panel3)}
.tree-ico{
  width:22px;height:22px;display:inline-flex;align-items:center;justify-content:center;
  flex-shrink:0;margin-right:5px;vertical-align:-5px;
}
.tree-ico svg{width:100%;height:100%;display:block;filter:drop-shadow(0 4px 8px rgba(0,0,0,.28))}
.tree-folder{color:#f2c85c}
.tree-home{color:#6fe1bb}
.tree-doc{color:#f5ecd2}
.mb-trow .tree-ico{margin-right:4px}
.mbr-ic .tree-ico{width:25px;height:25px;margin:0;vertical-align:0}
.mbr-ic .tree-ico svg{filter:drop-shadow(0 3px 6px rgba(0,0,0,.24))}
.mb-menu button .tree-ico,.mb-tree-toggle .tree-ico{
  width:18px;height:18px;margin-right:5px;vertical-align:-4px;
}
.mb-kids{margin-left:15px;border-left:1px solid var(--mb-line-soft);padding-left:5px}
.mb-tree-add{
  display:block;width:100%;margin-top:8px;padding:9px;border-radius:9px;cursor:pointer;background:none;
  color:var(--mb-dim);font-size:14px;font-weight:650;border:1px dashed var(--mb-line);text-align:center;font-family:inherit;
}
.mb-tree-add:hover{color:var(--mb-gold);border-color:var(--mb-gold-dark)}
.mb-pane{flex:1;min-width:0}
.mb-pane-head{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-bottom:10px;flex-wrap:wrap}
.mb-ctx{
  display:inline-flex;align-items:center;gap:6px;padding:8px 15px;border-radius:10px;cursor:pointer;
  background:var(--mb-panel);border:1px solid var(--mb-gold-dark);color:var(--mb-gold);
  font-weight:700;font-size:14px;font-family:inherit;flex-shrink:0;
}
.mb-ctx:hover{filter:brightness(1.2)}
.mb-tree-toggle{display:none}
/* Nút gập/mở cây thư mục trên desktop */
.mb-tree-collapse{
  flex-shrink:0;width:30px;height:30px;border-radius:9px;cursor:pointer;font-family:inherit;
  background:var(--mb-panel);border:1px solid var(--mb-line-soft);
  color:var(--mb-muted);font-size:14px;font-weight:800;line-height:1;
}
.mb-tree-collapse:hover{color:var(--mb-gold);border-color:var(--mb-gold-dark)}
@media (min-width:921px){.mb-ws.tree-off .mb-tree{display:none}}
@media (max-width:920px){.mb-tree-collapse{display:none}}
.breadcrumb{
  display:flex;align-items:center;gap:7px;flex-wrap:wrap;color:var(--mb-muted);
  font-size:15px;font-weight:700;margin-bottom:14px;
}
.breadcrumb a{
  display:inline-flex;align-items:center;gap:5px;color:var(--mb-mint);
  text-decoration:none;cursor:pointer;
}
.breadcrumb a:hover{color:var(--mb-gold)}
.breadcrumb .tree-ico{width:18px;height:18px;margin-right:0;vertical-align:0}

/* ===== Khối danh sách / hàng ===== */
.mb-panelbox{
  background:linear-gradient(180deg,rgba(16,35,26,.72),rgba(16,35,26,.5));
  border:1px solid rgba(99,142,112,.24);border-radius:16px;padding:14px;min-height:150px;
  box-shadow:inset 0 1px 0 rgba(255,255,255,.03);
}
.mb-list-summary{
  display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin:0 0 10px;padding:9px 10px;border-radius:11px;
  background:rgba(10,22,17,.42);border:1px solid rgba(143,174,155,.14);
  color:var(--mb-muted);font-size:13.5px;font-weight:650;
}
.mb-list-summary b{color:var(--mb-text);font-weight:800}
.mb-list-dot{width:4px;height:4px;border-radius:50%;background:var(--mb-dim)}
.mb-list-filter{color:var(--mb-gold)}
.mb-slabel{font-size:12px;font-weight:800;letter-spacing:.12em;text-transform:uppercase;color:#9fbaa9;padding:8px 10px 7px}
.mbr{
  display:flex;align-items:center;gap:12px;padding:10px 10px;border-radius:10px;
  transition:background .12s;position:relative;
}
.mbr:hover{background:var(--mb-panel2)}
.mbr + .mbr{border-top:1px solid var(--mb-line-soft)}
.mbr-ic{
  width:42px;height:42px;border-radius:11px;flex-shrink:0;font-size:18px;
  display:flex;align-items:center;justify-content:center;color:#eaf6ee;
}
.mbi-green{background:linear-gradient(135deg,#2f9e5f,#1c5c39)}
.mbi-blue{background:linear-gradient(135deg,#3d8fc9,#215a86)}
.mbi-purple{background:linear-gradient(135deg,#8a63c9,#553a85)}
.mbi-gold{background:linear-gradient(135deg,#c79a3a,#8a6a1f)}
.mbi-dim{background:linear-gradient(135deg,#3b5c48,#22392c)}
.mbi-red{background:linear-gradient(135deg,#5c3b3b,#392222)}
.mbr-info{flex:1;min-width:0}
.mbr-name{font-size:17px;font-weight:800;display:flex;align-items:center;gap:8px;flex-wrap:wrap;line-height:1.35}
.mbr-meta{font-size:13.5px;color:#9eb9aa;margin-top:5px;display:flex;gap:7px;align-items:center;flex-wrap:wrap;font-weight:600}
.mbr-meta .dot{width:3px;height:3px;border-radius:50%;background:var(--mb-dim)}
.mbr-acts{display:flex;gap:4px;align-items:center;flex-shrink:0;flex-wrap:wrap;justify-content:flex-end;position:relative}
.mbr-acts-more{display:flex;gap:4px;align-items:center}
/* Ở dạng danh sách: nhóm icon phụ ẩn đi, rê chuột vào hàng mới hiện — nổi đè lên phần
   ngày giờ (nền trùng màu nền hover của hàng) nên không chiếm chỗ của tên đề */
.mbr .mbr-acts-more{
  position:absolute;right:calc(100% + 6px);top:50%;transform:translateY(-50%);
  padding:3px 7px;border-radius:10px;background:var(--mb-panel2);
  opacity:0;pointer-events:none;transition:opacity .12s;
}
.mbr:hover .mbr-acts-more,.mbr:focus-within .mbr-acts-more{opacity:1;pointer-events:auto}
/* Máy cảm ứng (không có rê chuột) và màn hình hẹp: hiện đủ icon như thường */
@media (hover:none),(max-width:920px){
  .mbr .mbr-acts-more{position:static;transform:none;opacity:1;pointer-events:auto;background:none;padding:0}
}

/* Thẻ lưới gọn (dùng chung Bộ đề của tôi + Thư viện chung): icon cùng dòng với tên, thẻ thấp và chặt */
.mb-libcard{gap:9px;padding:13px}
.mb-libcard-head{display:flex;gap:11px;align-items:center;min-width:0}
.mb-libcard-info{flex:1;min-width:0}
.mb-libcard-acts{justify-content:flex-start}

.mb-chip{font-size:12px;font-weight:800;padding:4px 9px;border-radius:999px;letter-spacing:.02em;
  background:rgba(230,197,111,.13);color:var(--mb-gold);border:1px solid rgba(230,197,111,.3)}
.mb-chip.none{background:var(--mb-panel3);color:var(--mb-dim);border-color:var(--mb-line-soft)}
.mb-public-dot{font-size:13px;opacity:.75;vertical-align:middle;cursor:default}
.mb-draft-badge,.mb-ready-badge{
  display:inline-flex;align-items:center;gap:5px;font-size:11px;font-weight:800;padding:3px 8px;border-radius:999px;
  letter-spacing:.03em;text-transform:uppercase;border:1px solid transparent;white-space:nowrap;
}
.mb-draft-badge{background:rgba(230,197,111,.15);color:var(--mb-gold);border-color:rgba(230,197,111,.35)}
.mb-ready-badge{background:rgba(20,214,154,.12);color:#76e0bd;border-color:rgba(20,214,154,.3)}
.mb-tag{font-size:10.5px;font-weight:700;padding:3px 8px;border-radius:6px;letter-spacing:.04em}
.mb-tag.live{background:rgba(62,203,119,.13);color:#7fe3a8}
.mb-tag.bt{background:rgba(230,197,111,.13);color:var(--mb-gold)}

.mb-play,.mb-kt,.mb-soft{
  display:inline-flex;align-items:center;gap:6px;font-weight:700;font-size:13.5px;cursor:pointer;font-family:inherit;
  padding:8px 13px;border-radius:10px;transition:filter .12s;min-height:36px;
}
.mb-play{background:linear-gradient(135deg,#1e5c3a,#153f29);color:#bfe9cd;border:1px solid #2a6b45}
.mb-kt{background:none;color:var(--mb-muted);border:1px solid var(--mb-line)}
.mb-kt:hover{color:var(--mb-gold);border-color:rgba(230,197,111,.5)}
.mb-soft{background:var(--mb-panel);color:var(--mb-muted);border:1px solid var(--mb-line-soft)}
.mb-soft.danger{color:var(--mb-red);border-color:#5c3535}
.mb-play:hover,.mb-kt:hover,.mb-soft:hover{filter:brightness(1.18)}
/* Nút chỉ hiện icon; nhãn chữ là tooltip NỔI phía trên — không đổi bề rộng nút
   nên hàng không xô đẩy, không gây nháy khi rê chuột */
.mb-flip{
  position:relative;gap:0;justify-content:center;
  width:36px;min-width:36px;padding:0;flex-shrink:0;
}
.mb-flip .lbl{
  position:absolute;bottom:calc(100% + 7px);left:50%;transform:translateX(-50%);
  padding:4px 10px;border-radius:7px;white-space:nowrap;
  background:#0d2117;border:1px solid var(--mb-line);color:var(--mb-text);
  font-size:11.5px;font-weight:700;line-height:1.4;
  opacity:0;pointer-events:none;transition:opacity .12s;z-index:70;
  box-shadow:0 6px 18px rgba(0,0,0,.45);
}
.mb-flip:hover .lbl,.mb-flip:focus-visible .lbl{opacity:1}
.mb-more{
  width:36px;height:36px;border-radius:10px;background:var(--mb-panel);border:1px solid var(--mb-line-soft);
  color:var(--mb-muted);font-size:17px;cursor:pointer;font-family:inherit;
}
.mb-more:hover{color:var(--mb-gold)}

/* ===== Nâng cấp tài khoản ===== */
.mb-upgrade-shell{max-width:980px;margin:0 auto;width:100%}
.mb-upgrade-card{
  background:rgba(16,35,26,.7);border:1px solid var(--mb-line-soft);border-radius:18px;
  padding:18px;box-shadow:0 18px 42px rgba(0,0,0,.18);
}
.mb-upgrade-pay{display:grid;grid-template-columns:minmax(260px,360px) 1fr;gap:22px;align-items:center}
.mb-upgrade-qrbox{
  background:#f7f8f4;border-radius:16px;padding:14px;border:1px solid rgba(255,255,255,.16);
  display:flex;align-items:center;justify-content:center;
}
.mb-upgrade-qrbox img{width:100%;max-width:330px;display:block;border-radius:10px}
.mb-upgrade-info h2{margin:8px 0 14px;font-size:25px}
.mb-upgrade-line{
  display:flex;align-items:center;justify-content:space-between;gap:14px;
  border:1px solid var(--mb-line-soft);background:rgba(10,22,17,.45);border-radius:12px;padding:11px 13px;margin-bottom:9px;
}
.mb-upgrade-line span{color:var(--mb-muted);font-weight:650}
.mb-upgrade-line b{font-size:18px;color:var(--mb-text);text-align:right}
.mb-upgrade-code{color:var(--mb-gold)!important;letter-spacing:.04em}
.mb-upgrade-note{
  background:rgba(230,197,111,.1);border:1px solid rgba(230,197,111,.25);color:#e7d8aa;
  border-radius:12px;padding:11px 13px;font-size:13px;line-height:1.55;margin:12px 0;
}
.mb-upgrade-badge{
  display:inline-flex;align-items:center;border-radius:999px;padding:4px 10px;font-size:11px;font-weight:800;
  text-transform:uppercase;letter-spacing:.05em;border:1px solid transparent;
}
.mb-upgrade-badge.new{background:rgba(230,197,111,.13);color:var(--mb-gold);border-color:rgba(230,197,111,.28)}
.mb-upgrade-badge.wait{background:rgba(127,216,196,.12);color:#9ee8dc;border-color:rgba(127,216,196,.28)}
.mb-upgrade-badge.ok{background:rgba(62,203,119,.13);color:#86e2ad;border-color:rgba(62,203,119,.32)}
.mb-upgrade-badge.bad{background:rgba(224,122,106,.12);color:#f0a092;border-color:rgba(224,122,106,.3)}
.mb-upgrade-success{text-align:center;padding:34px 22px}
.mb-upgrade-success h2{margin:10px 0 6px}
.mb-upgrade-success p{color:var(--mb-muted);margin:0 0 20px}
.mb-upgrade-mark{
  width:70px;height:70px;border-radius:22px;margin:0 auto;
  display:flex;align-items:center;justify-content:center;font-size:38px;font-weight:900;
  color:#062216;background:linear-gradient(135deg,#8ef0bf,#1aa36f);
}
.mb-upgrade-admin-row .mbr-meta span{word-break:break-word}

/* Menu ⋯ */
.mb-menu{
  position:absolute;right:10px;top:58px;z-index:60;min-width:200px;
  background:#122b1f;border:1px solid var(--mb-line);border-radius:12px;padding:5px;
  box-shadow:0 14px 34px rgba(0,0,0,.5);
}
.mb-menu.left{right:auto;left:36px;top:30px}
.mb-menu button{
  display:flex;width:100%;gap:9px;align-items:center;border:none;background:none;cursor:pointer;font-family:inherit;
  padding:9px 11px;border-radius:8px;font-size:13px;color:var(--mb-text);text-align:left;
}
.mb-menu button:hover{background:var(--mb-panel3)}
.mb-menu button.danger{color:var(--mb-red)}

/* Chế độ lưới */
.mb-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:12px;padding:4px}
.mb-card{
  background:var(--mb-panel);border:1px solid var(--mb-line-soft);border-radius:15px;padding:16px;
  display:flex;flex-direction:column;gap:11px;transition:transform .12s,border-color .12s;position:relative;
}
.mb-card:hover{transform:translateY(-2px);border-color:var(--mb-gold-dark)}
.mb-card .top{display:flex;justify-content:space-between;align-items:flex-start;gap:8px}
.mb-card .mbr-name{font-size:16px}
.mb-card .mbr-acts{margin-top:auto}
.mb-card .mb-play,.mb-card .mb-kt{flex:1;justify-content:center;padding:9px 8px}

/* Thẻ lớp học */
.mb-classes{display:grid;grid-template-columns:repeat(auto-fill,minmax(215px,1fr));gap:14px}
.mb-class{
  background:linear-gradient(160deg,var(--mb-panel2),var(--mb-panel));
  border:1px solid var(--mb-line-soft);border-radius:16px;padding:20px 18px;cursor:pointer;font-family:inherit;
  display:flex;flex-direction:column;gap:5px;text-align:left;color:var(--mb-text);position:relative;
  transition:transform .12s,border-color .12s;
}
.mb-class:hover{transform:translateY(-3px);border-color:var(--mb-gold-dark)}
.mb-class .badge{
  width:44px;height:44px;border-radius:12px;display:flex;align-items:center;justify-content:center;
  font-weight:800;font-size:15px;margin-bottom:6px;
  background:rgba(230,197,111,.14);color:var(--mb-gold);
}
.mb-class h3{margin:0;font-size:17px;font-weight:800}
.mb-class p{margin:0;font-size:12.5px;color:var(--mb-muted)}
.mb-class .go{margin-top:8px;font-size:12.5px;color:var(--mb-gold);font-weight:600}
.mb-class.add{
  border-style:dashed;border-color:var(--mb-line);align-items:center;justify-content:center;
  color:var(--mb-dim);gap:8px;min-height:150px;background:transparent;
}
.mb-class.add:hover{color:var(--mb-gold);border-color:var(--mb-gold-dark)}
.mb-class .tmore{position:absolute;top:12px;right:12px}

/* Bộ lọc viên thuốc */
.mb-pills{display:flex;gap:7px;flex-wrap:wrap;margin-bottom:14px}
.mb-pill{
  padding:7px 15px;border-radius:999px;background:var(--mb-panel);cursor:pointer;font-family:inherit;
  border:1px solid var(--mb-line-soft);color:var(--mb-muted);font-size:13px;font-weight:600;
}
.mb-pill:hover{color:var(--mb-text)}
.mb-pill.on{background:linear-gradient(135deg,#f0d489,var(--mb-gold2));color:#241a05;border-color:transparent}

/* Thùng rác */
.mb-note{
  display:flex;gap:9px;align-items:center;background:var(--mb-panel);border:1px solid var(--mb-line-soft);
  border-radius:12px;padding:11px 14px;margin-bottom:14px;font-size:13px;color:var(--mb-muted);
}
.mb-trash-left{font-weight:700}
.mb-trash-left.soon{color:var(--mb-red)}

/* Trang đang phát triển */
.mb-coming{
  background:rgba(16,35,26,.55);border:1px dashed var(--mb-line);border-radius:20px;
  padding:64px 26px;text-align:center;
}
.mb-coming .badge{font-size:42px;margin-bottom:12px}
.mb-coming h2{
  font-size:23px;font-weight:800;margin:0 0 8px;
  background:linear-gradient(100deg,#f4dfa0,var(--mb-gold) 45%,#a37c25);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.mb-coming p{color:var(--mb-muted);font-size:14px;line-height:1.8;margin:0 0 18px}
.mb-coming .tag{
  display:inline-block;padding:7px 17px;border-radius:999px;font-size:12.5px;font-weight:700;
  background:var(--mb-panel);border:1px solid var(--mb-gold-dark);color:var(--mb-gold);
}

/* Hộp thoại Möbius (dùng .mb-overlay của app.css làm nền) */
.mb-modal{
  background:#122b1f !important;border:1px solid var(--mb-line);border-radius:18px !important;
  padding:24px !important;width:min(420px,92vw);
}
.mb-modal h3{margin:0 0 4px;font-size:17px;font-weight:800}
.mb-modal .sub{font-size:13px;color:var(--mb-muted);margin-bottom:16px}
.mb-choice{
  display:flex;align-items:center;gap:11px;width:100%;padding:12px 14px;border-radius:12px;margin-bottom:8px;
  background:var(--mb-panel);border:1px solid var(--mb-line-soft);font-size:14.5px;font-weight:600;
  text-align:left;cursor:pointer;font-family:inherit;color:var(--mb-text);
}
.mb-choice:hover{border-color:var(--mb-gold-dark);color:var(--mb-gold)}
.mb-choice .tree-ico{width:21px;height:21px;margin-right:2px;vertical-align:0}
.mb-choice .mini{
  width:32px;height:32px;border-radius:9px;display:flex;align-items:center;justify-content:center;
  font-size:12.5px;font-weight:800;background:rgba(230,197,111,.14);color:var(--mb-gold);flex-shrink:0;
}
.mb-check{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:10px;cursor:pointer;font-weight:600}
.mb-check:hover{background:var(--mb-panel3)}
.mb-check input{width:18px;height:18px;accent-color:var(--mb-gold)}
.mb-cancel{
  display:block;width:100%;text-align:center;color:var(--mb-dim);font-size:13px;padding:8px;margin-top:6px;
  background:none;border:none;cursor:pointer;font-family:inherit;
}
.mb-cancel:hover{color:var(--mb-text)}

.mb-empty{padding:38px 18px;text-align:center;color:var(--mb-muted);font-size:14.5px;line-height:1.7}
.mb-empty b{color:var(--mb-text)}

/* Tạo đề từ PDF */
.mb-pdf-layout{display:grid;grid-template-columns:minmax(320px,640px);gap:14px;align-items:start}
.mb-pdf-card{
  background:rgba(16,35,26,.62);border:1px solid var(--mb-line-soft);
  border-radius:16px;padding:14px;
}
.mb-pdf-field{display:flex;flex-direction:column;gap:6px;margin-bottom:12px}
.mb-pdf-field span,.mb-pdf-fileline{font-size:12.5px;font-weight:700;color:var(--mb-muted)}
.mb-pdf-field textarea{resize:vertical}
.mb-pdf-row{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.mb-pdf-fileline{
  display:flex;justify-content:space-between;align-items:center;gap:10px;
  margin:-2px 0 12px;padding:9px 11px;border-radius:10px;background:var(--mb-panel);
  border:1px dashed var(--mb-line);cursor:pointer;
}
.mb-pdf-fileline input{max-width:150px;font-size:11px;color:var(--mb-muted)}
.mb-pdf-note{margin-bottom:10px}
.mb-pdf-note span:first-child{
  width:24px;height:24px;border-radius:8px;display:inline-flex;align-items:center;justify-content:center;
  background:rgba(230,197,111,.12);color:var(--mb-gold);font-weight:900;flex-shrink:0;
}
.mb-pdf-msg{
  background:rgba(230,197,111,.11);border:1px solid rgba(230,197,111,.25);
  color:var(--mb-gold);border-radius:12px;padding:11px 14px;margin-bottom:14px;font-weight:700;font-size:13px;
}
.mb-pdf-progress{
  margin:14px 0;background:var(--mb-panel);border:1px solid var(--mb-line-soft);
  border-radius:12px;padding:12px;color:var(--mb-muted);font-size:13px;font-weight:700;
}
.mb-pdf-progress .bar{height:8px;border-radius:999px;background:#08140f;overflow:hidden;margin-bottom:8px}
.mb-pdf-progress .bar span{display:block;height:100%;background:linear-gradient(90deg,var(--mb-gold),#55d99a)}
.mb-pdf-review{margin-top:16px}
.mb-pdf-table{
  margin-top:12px;background:rgba(16,35,26,.55);border:1px solid var(--mb-line-soft);
  border-radius:16px;padding:8px;
}
.mb-pdf-qrow{
  display:grid;grid-template-columns:74px minmax(180px,1fr) 108px 118px minmax(120px,.4fr) 176px;
  gap:10px;align-items:center;padding:10px;border-radius:12px;position:relative;
}
.mb-pdf-qrow + .mb-pdf-qrow{border-top:1px solid var(--mb-line-soft)}
.mb-pdf-qrow.warn{background:rgba(230,197,111,.06)}
.mb-pdf-qrow label{display:flex;flex-direction:column;gap:4px;font-size:11.5px;font-weight:700;color:var(--mb-muted)}
.mb-pdf-qrow img{
  width:100%;max-height:170px;object-fit:contain;background:#fff;border-radius:10px;
  border:1px solid rgba(255,255,255,.08);
}
.mb-pdf-status{font-size:12px;color:var(--mb-muted);line-height:1.5}
.mb-pdf-status b{display:block;color:var(--mb-text)}
.mb-pdf-status span{color:var(--mb-gold)}
.mb-pdf-actions{display:flex;gap:7px;flex-wrap:wrap;justify-content:flex-end}
.mb-pdf-actions .mb-soft{padding:8px 10px;font-size:12px}
.mb-pdf-split-badge{
  display:inline-block;margin-top:5px;padding:3px 8px;border-radius:999px;
  background:rgba(255,143,125,.14);border:1px solid rgba(255,143,125,.4);
  color:#ff9d8c;font-size:11px;font-weight:800;line-height:1.3;
}
/* ===== Preview vạch cắt PDF kéo được ===== */
.mb-pdf-cutpreview{
  margin-top:14px;background:rgba(16,35,26,.55);border:1px solid var(--mb-line-soft);
  border-radius:16px;padding:14px;
}
.mb-cutpages{
  display:flex;gap:14px;overflow-x:auto;margin-top:12px;padding-bottom:6px;
  align-items:flex-start;
}
.mb-cutpage{flex-shrink:0}
.mb-cutpage-label{font-size:12px;font-weight:800;color:var(--mb-muted);margin-bottom:6px}
.mb-cutpage-stage{
  position:relative;display:inline-block;background:#fff;border-radius:10px;overflow:hidden;
  border:1px solid rgba(255,255,255,.14);cursor:copy;
}
.mb-cutpage-stage img{display:block;width:min(310px,72vw);height:auto;-webkit-user-drag:none;user-select:none}
.mb-cutline{
  position:absolute;left:0;right:0;height:0;cursor:ns-resize;touch-action:none;z-index:3;
}
.mb-cutline::before{
  content:"";position:absolute;left:0;right:0;top:-1px;height:2px;
  background:#14d69a;box-shadow:0 0 6px rgba(20,214,154,.7);
}
.mb-cutline::after{
  content:"";position:absolute;left:0;right:0;top:-8px;height:16px; /* vùng bắt chuột rộng hơn vạch */
}
.mb-cutline.unsafe::before{background:#ff5d45;box-shadow:0 0 8px rgba(255,93,69,.85)}
.mb-cutline-del{
  position:absolute;right:4px;top:-11px;width:22px;height:22px;border-radius:50%;border:none;
  background:rgba(10,22,17,.85);color:#ff9d8c;font-size:11px;font-weight:900;cursor:pointer;
  opacity:0;transition:opacity .12s;z-index:4;
}
.mb-cutline:hover .mb-cutline-del{opacity:1}
.mb-crop-modal{width:min(1500px,96vw) !important}
/* app.css kẹp .mb-overlay .card ở 440px — gỡ trần riêng cho hộp sửa ảnh */
.mb-overlay .mb-crop-modal{max-width:min(1500px,96vw);max-height:94vh}
.mb-crop-stage{display:flex;justify-content:center;align-items:center;margin-top:10px}
.mb-crop-wrap{
  position:relative;display:inline-block;max-width:100%;background:#fff;border-radius:12px;overflow:hidden;cursor:crosshair;
  border:1px solid rgba(255,255,255,.08);user-select:none;touch-action:none;
}
.mb-crop-wrap img{
  display:block;max-width:100%;max-height:74vh;background:#fff;pointer-events:none;
  -webkit-user-drag:none;user-select:none;
}
.mb-crop-box{
  position:absolute;border:2px solid #14d69a;background:rgba(20,214,154,.16);
  box-shadow:0 0 0 9999px rgba(0,0,0,.38);pointer-events:auto;cursor:move;
}
.mb-crop-box::before{
  content:"";position:absolute;inset:33.333% 0 auto 0;border-top:1px solid rgba(255,255,255,.65);
}
.mb-crop-box::after{
  content:"";position:absolute;inset:auto 0 33.333% 0;border-top:1px solid rgba(255,255,255,.65);
}
.mb-crop-handle{
  position:absolute;width:16px;height:16px;border:2px solid #fff;background:#14d69a;border-radius:50%;
  box-shadow:0 2px 8px rgba(0,0,0,.35);
}
.mb-crop-handle.nw{left:-9px;top:-9px;cursor:nwse-resize}
.mb-crop-handle.ne{right:-9px;top:-9px;cursor:nesw-resize}
.mb-crop-handle.sw{left:-9px;bottom:-9px;cursor:nesw-resize}
.mb-crop-handle.se{right:-9px;bottom:-9px;cursor:nwse-resize}
.mb-crop-tools{display:flex;gap:8px;flex-wrap:wrap;justify-content:center;margin-top:10px}
.mb-erase-rect{
  position:absolute;background:rgba(255,255,255,.92);
  border:1.5px dashed #e05a48;box-sizing:border-box;pointer-events:none;
}
/* ===== Trình sửa ảnh (Cắt / Xoá khung / Cọ tẩy / Hoàn tác) ===== */
.mb-imged-toolbar{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin:10px 0 8px}
.mb-imged-tool.on{
  background:rgba(230,197,111,.18);border-color:rgba(230,197,111,.6);color:var(--mb-gold);
}
.mb-imged-gap{flex:1}
.mb-imged-size{
  display:inline-flex;align-items:center;gap:8px;font-size:12px;font-weight:700;color:var(--mb-muted);
}
.mb-imged-size input{width:110px;accent-color:var(--mb-gold)}
.mb-imged-wrap{cursor:crosshair}
.mb-imged-wrap.mb-imged-brushing{cursor:cell}
.mb-imged-canvas{
  display:block;max-width:100%;max-height:74vh;width:auto;height:auto;background:#fff;
  -webkit-user-drag:none;user-select:none;
}
/* ảnh dải ngang (câu cắt từ PDF) → phóng hết bề rộng hộp cho dễ thao tác; class gắn bằng JS lúc nạp ảnh */
.mb-imged-canvas.wide{width:100%;max-height:none}
@media (max-width:920px){
  .mb-pdf-layout{grid-template-columns:1fr}
  .mb-pdf-qrow{grid-template-columns:58px 1fr;align-items:start}
  .mb-pdf-qrow img{grid-column:1 / -1;max-height:220px}
  .mb-pdf-status,.mb-pdf-actions{grid-column:1 / -1}
  .mb-pdf-actions{justify-content:flex-start}
}

/* ===== Avatar dạng ảnh (dùng chung cô + trò) ===== */
.ava-img{border-radius:8px;object-fit:cover;vertical-align:-6px;margin-right:6px;background:var(--mb-panel3)}
.avatar-grid{grid-template-columns:repeat(4,1fr) !important;gap:9px !important}
.avatar-btn{
  padding:0 !important;overflow:hidden;aspect-ratio:1;border-radius:14px !important;
  border:2px solid rgba(255,255,255,.12) !important;
}
.avatar-btn img{width:100%;height:100%;object-fit:cover;display:block}
.avatar-btn.sel{border-color:var(--mb-gold) !important;box-shadow:0 0 0 3px rgba(230,197,111,.28)}
.pod-name .ava-img{vertical-align:-5px}

/* ===== Trang học sinh ===== */
.st-logo{text-align:center;padding-top:18px;margin-bottom:14px}
.st-logo img{width:130px;filter:drop-shadow(0 8px 18px rgba(0,0,0,.5))}
.st-logo .name{
  font-weight:800;font-size:21px;letter-spacing:.32em;margin-left:.32em;display:block;margin-top:4px;
  background:linear-gradient(100deg,#f4dfa0,var(--mb-gold) 45%,#a37c25);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.st-logo .slogan{font-size:11.5px;color:var(--mb-dim);margin-top:3px;font-weight:500}
.st-logo .teacher-label{
  margin-top:12px;color:var(--mb-gold);font-size:13.5px;font-weight:750;letter-spacing:.06em;
}
.st-card{
  max-width:430px;margin:0 auto;background:rgba(16,35,26,.7) !important;
  border:1px solid var(--mb-line-soft) !important;border-radius:20px !important;padding:24px 22px !important;
}
.st-pin{
  font-size:27px !important;font-weight:800 !important;letter-spacing:.3em !important;text-align:center !important;
  background:var(--mb-panel2) !important;color:var(--mb-text) !important;border:1.5px solid var(--mb-line) !important;
  border-radius:13px !important;padding:14px 8px 14px calc(8px + .3em) !important;
}
.st-pin::placeholder{letter-spacing:.05em;font-size:15px;font-weight:500;color:var(--mb-dim)}
.st-pin:focus{border-color:var(--mb-gold-dark) !important}
.st-name{
  text-align:center !important;background:var(--mb-panel2) !important;color:var(--mb-text) !important;
  border:1.5px solid var(--mb-line) !important;border-radius:13px !important;font-weight:600 !important;
}
.st-name:focus{border-color:var(--mb-gold-dark) !important}
.st-go{
  background:linear-gradient(135deg,#f0d489,var(--mb-gold2)) !important;color:#241a05 !important;
  box-shadow:0 8px 22px rgba(199,154,58,.3);
}
.st-hint{margin-top:14px;font-size:12.5px;color:var(--mb-dim);line-height:1.7;text-align:center}
.st-hint b{color:var(--mb-muted)}
.mb-footer{
  max-width:960px;margin:22px auto 0;padding:0 14px;text-align:center;
  display:flex;align-items:center;justify-content:center;gap:6px 12px;flex-wrap:wrap;
  color:rgba(241,235,218,.55);font-size:12px;line-height:1.6;
}
.mb-main .mb-footer{margin-top:auto;padding-top:34px;padding-bottom:22px}
.mb-footer a{color:var(--mb-gold);font-weight:700;text-decoration:none}
.mb-footer a:hover{text-decoration:underline}
.st-room{
  display:inline-block;background:var(--mb-panel);border:1px solid var(--mb-gold-dark);color:var(--mb-gold);
  padding:7px 18px;border-radius:999px;font-weight:700;font-size:13px;letter-spacing:.08em;
}
.st-meava{
  width:92px;height:92px;border-radius:26px;border:2px solid var(--mb-gold);overflow:hidden;margin:0 auto;
  box-shadow:0 10px 30px rgba(230,197,111,.15);background:var(--mb-panel3);
}
.st-meava img{width:100%;height:100%;object-fit:cover}
.st-friends{display:flex;flex-wrap:wrap;gap:9px;justify-content:center;margin-top:18px}
.st-friend{
  display:flex;align-items:center;gap:7px;background:var(--mb-panel);border:1px solid var(--mb-line-soft);
  border-radius:999px;padding:5px 13px 5px 6px;font-size:13px;font-weight:600;color:var(--mb-muted);
  animation:pop .3s ease;
}
.st-friend img{width:25px;height:25px;border-radius:50%;object-fit:cover}
.st-dots span{display:inline-block;animation:mbblink 1.4s infinite}
.st-dots span:nth-child(2){animation-delay:.2s}
.st-dots span:nth-child(3){animation-delay:.4s}
@keyframes mbblink{0%,60%,100%{opacity:.2}30%{opacity:1}}

/* ===== Soạn đề dạng SLIDE (cột trái danh sách, phải khung soạn lớn) ===== */
body.mb-focus.mb-editor-mode .mb-main .wrap{
  max-width:min(1500px,calc(100vw - 72px));padding-left:32px;padding-right:32px;
}
.ed-topbar{display:flex;align-items:center;justify-content:space-between;gap:14px;margin:14px 0 14px;flex-wrap:wrap}
.ed-title-input{
  flex:1;min-width:320px;font-size:18px!important;font-weight:850!important;
  background:rgba(239,244,239,.82)!important;border-color:rgba(255,255,255,.18)!important;
}
.ed-top-actions{display:flex;align-items:center;gap:8px;flex-wrap:wrap;flex-shrink:0}
.ed-top-actions .ed-draft-btn{
  background:rgba(255,255,255,.13);border:1px solid rgba(255,255,255,.12);color:#eef5ec;
}
.ed-top-actions .ed-back-btn{
  background:rgba(255,255,255,.07);border:1px solid rgba(255,255,255,.08);color:#d6e1d9;
  box-shadow:none;
}
.ed-top-actions .ed-back-btn:hover{background:rgba(255,255,255,.11);color:#eef5ec}
.ed-meta-bar{
  display:grid;grid-template-columns:minmax(260px,1.1fr) minmax(240px,1fr) minmax(190px,.8fr) minmax(170px,.7fr);
  gap:10px;margin-bottom:18px;align-items:stretch;
}
.ed-meta-group{
  display:flex;align-items:center;gap:9px;flex-wrap:wrap;
  background:rgba(16,35,26,.55);border:1px solid rgba(143,174,155,.18);
  border-radius:13px;padding:10px 12px;min-height:46px;
}
.ed-meta-label{
  color:#9eb9aa;font-size:12px;font-weight:850;text-transform:uppercase;letter-spacing:.08em;
}
.ed-meta-value{display:inline-flex;align-items:center;gap:5px;color:var(--mb-muted);font-size:14px;font-weight:700;min-width:0}
.ed-meta-value b,.ed-meta-group b{color:#ffd166}
.ed-meta-value .tree-ico{width:19px;height:19px;margin:0}
.ed-meta-theme,.ed-meta-privacy{justify-content:space-between}
.ed-public-hint{
  grid-column:1 / -1;color:var(--mb-muted);font-size:12.5px;line-height:1.5;
  padding:0 4px;margin-top:-2px;
}
.ed-shell{display:flex;gap:18px;align-items:flex-start;margin-top:4px;width:100%}
.ed-slides{
  width:292px;flex-shrink:0;background:rgba(16,35,26,.6);
  border:1px solid var(--mb-line-soft);border-radius:16px;padding:10px;
  max-height:calc(100vh - 170px);overflow-y:auto;
  display:flex;flex-direction:column;gap:8px;
}
.ed-slides.ed-dragging{cursor:grabbing;user-select:none}
.ed-slide{
  display:flex;align-items:flex-start;gap:11px;min-height:116px;padding:14px 12px;border-radius:12px;cursor:grab;position:relative;
  background:var(--mb-panel);border:1.5px solid var(--mb-line-soft);
  transition:border-color .12s,background .12s,transform .12s,box-shadow .12s;
  touch-action:none;
  flex-shrink:0; /* cột .ed-slides có max-height: không cho bóp thẻ — thẻ bị nén sẽ che mất hàng nút dưới đáy */
}
.ed-slide:hover{border-color:var(--mb-line)}
.ed-slide.sel{border-color:var(--mb-gold-dark);background:var(--mb-panel3);box-shadow:0 0 0 2px rgba(230,197,111,.15)}
.ed-slide.is-slide{background:rgba(20,43,32,.35);border-style:dashed}
.ed-slide.is-slide:hover{border-color:var(--mb-line-soft)}
.ed-slide.is-slide.sel{background:rgba(24,53,38,.55);border-style:solid}
.ed-slide.is-slide .ed-slide-thumb-ic{opacity:.75}
.ed-slide.is-slide .ed-slide-type{opacity:.75}
.ed-slide.drag-source{
  opacity:.32;cursor:grabbing;
}
.ed-slide.drag-ghost{
  position:fixed;z-index:9999;pointer-events:none;cursor:grabbing;
  margin:0;opacity:.96;transform:translate(0,0) scale(1.035);
  border-color:var(--mb-gold);background:#203f2f;
  box-shadow:0 14px 28px rgba(0,0,0,.38),0 0 0 3px rgba(230,197,111,.22);
  transition:none;
}
.ed-slide.drag-before::before,.ed-slide.drag-after::after{
  content:"";position:absolute;left:8px;right:8px;height:4px;border-radius:999px;
  background:linear-gradient(90deg,#ffd66b,#3ecb77);box-shadow:0 0 14px rgba(255,214,107,.55);
}
.ed-slide.drag-before::before{top:-7px}
.ed-slide.drag-after::after{bottom:-7px}
.ed-slide-num{
  width:30px;height:30px;border-radius:9px;flex-shrink:0;font-size:13px;font-weight:850;
  display:flex;align-items:center;justify-content:center;background:var(--mb-panel3);color:var(--mb-muted);
}
.ed-slide.sel .ed-slide-num{background:var(--mb-gold);color:#241a05}
.ed-slide-thumb-img{width:42px;height:42px;border-radius:10px;object-fit:cover;flex-shrink:0;background:#fff}
.ed-slide-thumb-ic{
  width:42px;height:42px;border-radius:10px;flex-shrink:0;display:flex;align-items:center;justify-content:center;
  background:var(--mb-panel2);font-size:17px;
}
.ed-slide-info{flex:1;min-width:0}
.ed-slide-type{font-size:11.5px;font-weight:800;color:#9eb9aa;letter-spacing:.03em;line-height:1.25}
.ed-slide-points{
  display:inline-flex;align-items:center;margin-left:4px;padding:1px 6px;border-radius:999px;
  background:rgba(230,197,111,.16);border:1px solid rgba(230,197,111,.32);
  color:var(--mb-gold);font-size:10.5px;font-weight:900;letter-spacing:0;
}
.ed-slide-prev{
  font-size:13.5px;color:var(--mb-muted);overflow:hidden;margin-top:6px;line-height:1.35;
  display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;white-space:normal;
}
/* Hàng 3 icon thao tác nhanh dưới đáy mỗi thẻ câu: chèn / nhân đôi / xoá */
.ed-slide{flex-wrap:wrap}
.ed-slide-actions{
  flex-basis:100%;display:flex;gap:6px;margin-top:9px;padding-top:8px;
  border-top:1px solid var(--mb-line-soft);
}
.ed-slide-actions button{
  flex:1;min-width:0;display:inline-flex;align-items:center;justify-content:center;
  height:27px;border-radius:8px;cursor:pointer;font-family:inherit;padding:0;
  border:1px solid var(--mb-line-soft);background:none;color:var(--mb-dim);font-size:13px;line-height:1;
}
.ed-slide-actions button:hover{color:var(--mb-gold);border-color:var(--mb-gold-dark);background:var(--mb-panel3)}
.ed-slide-actions button.danger:hover{color:var(--mb-red);border-color:rgba(224,122,106,.5);background:rgba(224,122,106,.08)}
.ed-add{
  display:block;width:100%;padding:11px;border-radius:12px;cursor:pointer;font-family:inherit;
  background:none;border:1.5px dashed var(--mb-line);color:var(--mb-dim);font-weight:600;font-size:13.5px;
}
.ed-add:hover{color:var(--mb-gold);border-color:var(--mb-gold-dark)}
.ed-add-slide{margin-top:8px;border-style:solid;background:rgba(127,216,196,.05);color:#9ee8dc;border-color:rgba(127,216,196,.26)}
.ed-add-slide:hover{color:#c8fff2;border-color:rgba(127,216,196,.5)}
.ed-canvas{
  flex:1;min-width:0;background:var(--mb-panel);border:1px solid var(--mb-line-soft);
  border-radius:16px;padding:28px;
}
.ed-canvas-num{font-weight:800;font-size:15px;color:var(--mb-gold)}
.ed-point-toggle{
  height:44px;padding:0 14px;border-radius:12px;border:1px solid rgba(230,197,111,.24);
  background:rgba(255,255,255,.1);color:var(--mb-muted);font-family:inherit;
  font-size:14px;font-weight:850;cursor:pointer;white-space:nowrap;
}
.ed-point-toggle:hover{border-color:rgba(230,197,111,.48);color:var(--mb-gold)}
.ed-point-toggle.on{
  background:rgba(230,197,111,.16);border-color:rgba(230,197,111,.56);color:var(--mb-gold);
  box-shadow:inset 0 0 0 1px rgba(230,197,111,.12);
}
.ed-field-head{display:flex;justify-content:space-between;align-items:flex-end;gap:12px;margin-top:8px;margin-bottom:8px}
.ed-field-label{
  color:#d5decf;font-size:13px;font-weight:900;text-transform:uppercase;letter-spacing:.08em;
}
.ed-field-sub{color:var(--mb-muted);font-size:12.5px;font-weight:650;margin-top:3px}
.ed-preview-label{margin-top:14px;margin-bottom:7px}
.ed-head-tools{display:flex;align-items:center;gap:7px;flex-wrap:wrap;justify-content:flex-end}
.ed-fmt-btn{
  display:inline-flex;align-items:center;justify-content:center;width:34px;height:34px;
  border-radius:10px;border:1px solid rgba(143,174,155,.3);
  background:rgba(255,255,255,.06);color:#d5decf;font-family:inherit;
  font-size:14px;cursor:pointer;
}
.ed-fmt-btn b{font-weight:900}
.ed-fmt-btn:hover{border-color:rgba(230,197,111,.5);color:var(--mb-gold);background:rgba(230,197,111,.1)}
.ed-math-toggle{
  display:inline-flex;align-items:center;gap:7px;min-width:0;height:34px;padding:0 12px;
  border-radius:10px;border:1px solid rgba(230,197,111,.34);
  background:rgba(230,197,111,.09);color:var(--mb-gold);font-family:inherit;
  font-size:12.5px;font-weight:800;cursor:pointer;white-space:nowrap;
}
.ed-math-toggle:hover,.ed-math-toggle.on{background:rgba(230,197,111,.18);border-color:rgba(230,197,111,.58)}
.ed-math-panel{
  margin:8px 0 10px;padding:10px;border-radius:12px;background:rgba(10,22,17,.45);
  border:1px solid rgba(143,174,155,.18);
}
.ed-math-note{color:var(--mb-muted);font-size:12.5px;font-weight:650;line-height:1.5;margin-bottom:8px}
.ed-math-note b,.ed-math-note code{color:var(--mb-gold)}
.ed-math-tabs{display:flex;gap:6px;margin-bottom:9px;flex-wrap:wrap}
.ed-math-tab{
  display:inline-flex;align-items:center;gap:6px;flex:1;min-width:76px;justify-content:center;
  padding:7px 10px;border-radius:9px;border:1px solid rgba(143,174,155,.22);
  background:rgba(255,255,255,.04);color:var(--mb-muted);font-family:inherit;
  font-size:12px;font-weight:800;cursor:pointer;white-space:nowrap;
}
.ed-math-tab-sym{font-size:13.5px;line-height:1;color:var(--mb-gold)}
.ed-math-tab-sym sub,.ed-math-tab-sym sup{color:inherit}
.ed-math-tab-label{opacity:.9}
.ed-math-tab:hover{border-color:rgba(230,197,111,.4)}
.ed-math-tab.on{background:rgba(230,197,111,.16);border-color:rgba(230,197,111,.6);color:var(--mb-gold)}
.ed-canvas .math-toolbar{gap:8px;margin:0}
.ed-canvas .math-toolbar button{min-width:34px;padding:6px 10px}
.ed-canvas .math-toolbar button sub,.ed-canvas .math-toolbar button sup{font-size:.72em}
.math-toolbar button .snip-kx{display:inline-flex;align-items:center;justify-content:center;line-height:1}
.math-toolbar button .snip-kx .katex{font-size:1.08em}
@media (max-width:760px){
  .ed-math-tab{min-width:64px;padding:6px 7px;font-size:11px}
  .ed-canvas .math-toolbar button{padding:6px 8px;font-size:12.5px}
}
.ed-canvas #qtext{min-height:110px}
.ed-canvas .preview-box{
  margin-top:0;background:rgba(239,244,239,.82);border:1px solid rgba(255,255,255,.2);
  color:#173726;
}
@media (max-width:920px){
  body.mb-focus.mb-editor-mode .mb-main .wrap{max-width:100%;padding-left:16px;padding-right:16px}
  .ed-topbar{align-items:stretch}
  .ed-title-input{min-width:100%}
  .ed-meta-bar{grid-template-columns:1fr}
  .ed-shell{flex-direction:column}
  .ed-slides{width:100%;max-height:220px;flex-direction:row;overflow-x:auto;overflow-y:hidden}
  .ed-slide{min-width:190px;flex-shrink:0}
  .ed-canvas{padding:16px}
}

@media (max-width:920px){
  .mb-shell{flex-direction:column}
  .mb-side{width:100%;height:auto;position:static;flex-direction:row;flex-wrap:wrap;align-items:center;gap:6px;padding:12px 14px}
  .mb-main .wrap{min-height:auto}
  .mb-brand{padding:0;display:flex;align-items:center;gap:8px}
  .mb-brand img{width:44px;margin:0}
  .mb-brand .slogan{display:none}
  .mb-brand .name{font-size:15px}
  .mb-create{margin:0;padding:9px 13px;font-size:14.5px}
  .mb-nav{width:auto;min-height:42px;padding:8px 11px;font-size:14px}
  .mb-nav .ic{display:none}
  .mb-head .icon{width:48px;height:48px}
  .mb-head .icon svg{width:32px;height:32px}
  .mb-head h1{font-size:24px}
  .mb-head p{font-size:14.5px}
  .mb-donate,.mb-user .who,.mb-pro-badge,.mb-upgrade-ad{display:none!important}
  .mb-user{margin:0;border:none;background:none;padding:4px}
  .mb-ws{flex-direction:column}
  .mb-tree{width:100%;max-height:260px;display:none}
  .mb-tree.show{display:block}
  .mb-tree-toggle{
    display:inline-flex;align-items:center;gap:7px;margin-bottom:10px;cursor:pointer;font-family:inherit;
    padding:9px 15px;border-radius:11px;background:var(--mb-panel);
    border:1px solid var(--mb-line-soft);color:var(--mb-gold);font-weight:700;font-size:14px;
  }
  .mbr{flex-wrap:wrap}
  .mbr-acts{width:100%;justify-content:flex-start}
}

/* ===== Video YouTube trong câu hỏi ===== */
.yt-embed{display:block;width:100%;aspect-ratio:16/9;border:0;border-radius:12px;margin-top:12px;background:#000}

/* ===== Trắc nghiệm nhiều đáp án ===== */
.multi-badge{
  display:block;text-align:center;margin-top:14px;padding:9px 14px;border-radius:11px;
  background:rgba(230,197,111,.14);border:1px solid var(--mb-gold-dark);
  color:var(--mb-gold);font-weight:800;font-size:14px;
}
.mc-opt.mc-toggle{position:relative;opacity:.92}
.mc-opt.mc-toggle.sel{
  outline:4px solid #fff;outline-offset:-4px;opacity:1;
  box-shadow:0 0 0 3px rgba(255,255,255,.35), 0 6px 18px rgba(0,0,0,.3);
}
.mc-opt.mc-toggle.sel::after{
  content:"✓";position:absolute;top:6px;right:9px;font-size:17px;font-weight:900;color:#fff;
}

/* Link mời vào phòng trong sảnh chờ */
.host-join-link{
  display:flex;align-items:center;justify-content:center;gap:9px;flex-wrap:wrap;
  margin-top:8px;
}
.host-join-link .url{
  font-size:14.5px;font-weight:750;color:var(--mb-mint);word-break:break-all;
  user-select:all; /* bấm một phát là chọn cả link, tiện copy tay */
}

/* ===== Bục vinh danh ===== */
/* ===== PIN cố định trên màn tổ chức chơi ===== */
.host-pin-badge{
  position:fixed;top:74px;right:18px;z-index:80;
  display:flex;align-items:baseline;gap:9px;
  padding:10px 15px;border-radius:16px;
  background:rgba(10,22,17,.88);border:1px solid rgba(230,197,111,.45);
  color:var(--mb-gold);box-shadow:0 10px 28px rgba(0,0,0,.32),0 0 0 1px rgba(255,255,255,.04) inset;
  backdrop-filter:blur(10px);
}
.host-pin-badge span{font-size:11px;font-weight:900;letter-spacing:.16em;opacity:.72}
.host-pin-badge b{font-size:28px;font-weight:900;letter-spacing:.12em;line-height:1}
@media (max-width:760px){
  .host-pin-badge{top:62px;right:10px;padding:8px 11px;border-radius:13px}
  .host-pin-badge span{font-size:9px}
  .host-pin-badge b{font-size:20px}
}

/* Tên bài kiểm tra ngay dưới tiêu đề bục vinh danh */
.podium-quiz{
  margin:-10px 0 16px;text-align:center;color:var(--mb-muted);
  font-size:17px;font-weight:750;letter-spacing:.01em;
}
.podium-title{
  margin:10px 0 18px;text-align:center;font-size:48px;font-weight:800;line-height:1.12;
  color:#fff8e8;text-shadow:0 4px 18px rgba(0,0,0,.36);
}
.podium-title.small{font-size:32px;margin-top:22px}
.podium{
  display:flex;align-items:flex-end;justify-content:center;gap:22px;
  max-width:980px;margin:26px auto 18px;padding:0 10px;min-height:410px;
}
.pod-slot{
  flex:0 1 154px;max-width:172px;text-align:center;opacity:0;
  transform:translateY(42px) scale(.96);
  transition:opacity .5s ease, transform .5s ease;
}
.pod-slot.show{opacity:1;transform:translateY(0) scale(1)}
.pod-person{
  min-height:178px;margin-bottom:12px;
  display:flex;flex-direction:column;align-items:center;justify-content:flex-end;
}
.pod-avatar{
  width:88px;height:88px;border-radius:50%;padding:4px;position:relative;
  background:linear-gradient(135deg,#ffe39b,#b27a18);
  box-shadow:0 8px 22px rgba(0,0,0,.35),0 0 0 4px rgba(230,197,111,.12);
}
.pod-avatar-ring{
  width:100%;height:100%;border-radius:50%;overflow:hidden;background:var(--mb-panel3);
  display:flex;align-items:center;justify-content:center;font-size:34px;
}
.pod-avatar .ava-img{width:100%;height:100%;object-fit:cover;border-radius:50%;margin:0;vertical-align:middle}
.pod-rank-0 .pod-avatar{width:112px;height:112px;box-shadow:0 10px 28px rgba(0,0,0,.42),0 0 0 7px rgba(230,197,111,.16)}
.pod-rank-0 .pod-avatar::before{
  content:"";position:absolute;inset:-20px -24px -14px;border-radius:50%;
  border-left:7px double rgba(199,154,58,.9);border-right:7px double rgba(199,154,58,.9);
  pointer-events:none;
}
.pod-rank-3 .pod-avatar,.pod-rank-4 .pod-avatar{width:78px;height:78px}
.pod-name{
  max-width:170px;margin-top:10px;color:#fff8e8;font-size:20px;font-weight:900;line-height:1.22;
  word-break:break-word;text-shadow:0 3px 12px rgba(0,0,0,.45);
}
.pod-score{
  color:#ffd66b;font-size:26px;font-weight:900;line-height:1.15;text-shadow:0 3px 12px rgba(0,0,0,.45);
}
.pod-rank-3 .pod-name,.pod-rank-4 .pod-name{font-size:17px}
.pod-rank-3 .pod-score,.pod-rank-4 .pod-score{font-size:22px}
.pod-col{
  height:var(--pod-h);width:100%;border-radius:16px 16px 0 0;
  display:flex;align-items:flex-start;justify-content:center;padding-top:58px;
  background:linear-gradient(180deg,#ffc858 0%,#d67809 78%,#ae4e00 100%) !important;
  border:1px solid rgba(255,236,180,.34);
  box-shadow:inset 0 1px 0 rgba(255,255,255,.25),0 -8px 30px rgba(255,165,38,.18);
}
#pod-0 .pod-col{width:168px}
#pod-1 .pod-col,#pod-2 .pod-col{width:158px}
#pod-3 .pod-col,#pod-4 .pod-col{width:136px;padding-top:28px}
.pod-medal{
  width:62px;height:62px;border-radius:50%;display:flex;align-items:center;justify-content:center;
  position:relative;color:#8a4502;background:linear-gradient(180deg,#ffe589,#f3aa28);
  border:4px solid rgba(255,230,150,.9);box-shadow:0 7px 14px rgba(0,0,0,.24);
  font-size:30px;font-weight:900;
}
.pod-medal::before{
  content:"";position:absolute;top:-25px;left:15px;width:28px;height:28px;
  background:linear-gradient(135deg,#1d8cff,#1757d5);border-radius:6px 14px 4px 14px;
  transform:rotate(-34deg);box-shadow:24px 15px 0 -2px #2278f2;z-index:-1;
}
#pod-1 .pod-medal{background:linear-gradient(180deg,#f3f5f7,#aab0b8);border-color:#edf2f6;color:#444}
#pod-2 .pod-medal{background:linear-gradient(180deg,#f1b16e,#ba6631);border-color:#f6bf84;color:#6f350d}
#pod-3 .pod-medal,#pod-4 .pod-medal{
  width:auto;height:auto;background:none;border:0;box-shadow:none;color:#ffe3a7;
  font-size:30px;text-shadow:0 2px 10px rgba(0,0,0,.32);
}
#pod-3 .pod-medal::before,#pod-4 .pod-medal::before{display:none}
.podium-note{
  text-align:center;color:rgba(241,235,218,.7);font-size:17px;font-weight:600;margin:14px auto 0;
}
.podium-actions{display:flex;align-items:center;justify-content:center;gap:20px;flex-wrap:wrap;margin-top:22px}
.podium-action{min-width:260px;border-radius:18px;font-size:20px;padding:18px 28px}
@media (max-width:760px){
  .podium-title{font-size:32px;margin-top:10px}
  .podium{gap:8px;min-height:300px;margin-top:18px;padding:0 4px}
  .pod-slot{flex-basis:72px;max-width:86px}
  .pod-person{min-height:132px;margin-bottom:8px}
  .pod-avatar{width:56px;height:56px;padding:3px}
  .pod-rank-0 .pod-avatar{width:72px;height:72px}
  .pod-rank-0 .pod-avatar::before{inset:-12px -16px -10px;border-left-width:4px;border-right-width:4px}
  .pod-rank-3 .pod-avatar,.pod-rank-4 .pod-avatar{width:50px;height:50px}
  .pod-name{font-size:12.5px;max-width:86px}
  .pod-score{font-size:18px}
  .pod-rank-3 .pod-name,.pod-rank-4 .pod-name{font-size:11.5px}
  .pod-rank-3 .pod-score,.pod-rank-4 .pod-score{font-size:16px}
  .pod-col{height:calc(var(--pod-h) * .62);border-radius:10px 10px 0 0;padding-top:36px}
  #pod-0 .pod-col{width:82px}
  #pod-1 .pod-col,#pod-2 .pod-col{width:76px}
  #pod-3 .pod-col,#pod-4 .pod-col{width:66px;padding-top:18px}
  .pod-medal{width:42px;height:42px;font-size:21px;border-width:3px}
  .pod-medal::before{top:-18px;left:10px;width:20px;height:20px;box-shadow:17px 11px 0 -2px #2278f2}
  #pod-3 .pod-medal,#pod-4 .pod-medal{font-size:20px}
  .podium-note{font-size:13px;padding:0 12px}
  .podium-actions{gap:10px}
  .podium-action{min-width:0;width:100%;max-width:320px;font-size:16px;padding:14px 18px}
}

/* ===== Chọn theme trong trang soạn đề ===== */
.theme-modal{width:min(760px,94vw)}
.theme-section{margin:4px 0 16px}
.theme-section-title{
  font-size:12px;font-weight:800;letter-spacing:.08em;text-transform:uppercase;
  color:var(--mb-gold);margin:0 0 8px;
}
.theme-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(136px,1fr));gap:10px;margin:4px 0 8px}
.theme-grid-default{grid-template-columns:minmax(136px,180px)}
.theme-card{
  border:2px solid var(--mb-line-soft);border-radius:13px;padding:7px;cursor:pointer;
  background:var(--mb-panel);font-family:inherit;color:var(--mb-text);text-align:center;
}
.theme-card:hover{border-color:var(--mb-line)}
.theme-card.sel{border-color:var(--mb-gold);box-shadow:0 0 0 3px rgba(230,197,111,.2)}
.theme-thumb{
  display:block;height:64px;border-radius:9px;margin-bottom:6px;
  background:radial-gradient(300px 160px at 60% 0%, #123023, #0a1611);
  background-size:cover;background-position:center;
}
.theme-name{
  min-height:32px;display:flex;align-items:center;justify-content:center;
  font-size:12.5px;font-weight:700;line-height:1.25;
}
@media (max-width:760px){
  .mb-upgrade-card{padding:14px;border-radius:15px}
  .mb-upgrade-pay{grid-template-columns:1fr;gap:14px}
  .mb-upgrade-qrbox img{max-width:280px}
  .mb-upgrade-info h2{font-size:21px}
  .mb-upgrade-line{align-items:flex-start;flex-direction:column;gap:5px}
  .mb-upgrade-line b{text-align:left;font-size:16px;word-break:break-word}
}

/* ---- Khung "Xem lại câu hỏi" sau khi có kết quả (trang học sinh) ---- */
.st-review{text-align:left}
.st-review .q-img{max-height:260px}
.st-rv{position:relative}
.st-rv.st-rv-dim{opacity:.45;filter:saturate(.55)}
.st-rv.st-rv-cor{box-shadow:0 0 0 3px #6EE7B7, 0 0 18px rgba(110,231,183,.35)}
.st-rv-tag{
  display:inline-block;margin-left:8px;padding:2px 9px;border-radius:999px;
  font-size:11.5px;font-weight:800;letter-spacing:.2px;vertical-align:middle;
  background:rgba(0,0,0,.4);color:#fff;white-space:nowrap;
}
.st-rv-tag.ok{background:#065F46;color:#6EE7B7}
.st-rv-tag.me{background:rgba(255,255,255,.28)}

/* ---- Màn CÔNG BỐ ĐÁP ÁN của cô: đề bài giữ cỡ lớn, dưới chia 2 cột ---- */
.mb-rv-grid{
  display:grid;grid-template-columns:minmax(0,1.5fr) minmax(0,1fr);
  gap:14px;align-items:start;
}
.mb-rv-main,.mb-rv-side{padding:16px 18px}
.mb-rv-answer{
  background:rgba(110,231,183,.13);border:1px solid rgba(110,231,183,.42);
  border-radius:14px;padding:12px 16px;
}
.mb-rv-answer-label{
  font-size:12.5px;font-weight:800;letter-spacing:.6px;text-transform:uppercase;
  color:#6EE7B7;opacity:.92;margin-bottom:2px;
}
.mb-rv-answer-val{
  font-size:clamp(26px,3.2vw,40px);font-weight:900;color:#6EE7B7;
  line-height:1.25;word-break:break-word;
}
.mb-rv-answer-val .katex{font-size:1em}

.mb-rv-stats{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-top:11px}
.mb-rv-stat{border-radius:11px;padding:8px 10px;line-height:1.15}
.mb-rv-stat b{display:block;font-size:26px;font-weight:900}
.mb-rv-stat span{font-size:12.5px;font-weight:700;opacity:.85}
.mb-rv-stat.good{background:rgba(110,231,183,.16);color:#6EE7B7}
.mb-rv-stat.bad{background:rgba(248,113,113,.16);color:#FF9A9A}
.mb-rv-stat.none{background:rgba(255,255,255,.08);color:var(--mb-text)}

.mb-rv-dist-label{margin:14px 0 7px}
.mb-rv-dist{display:grid;gap:7px}
.mb-rv-drow{display:flex;align-items:center;gap:10px;flex-wrap:nowrap}
.mb-rv-dlabel{
  min-width:74px;max-width:210px;font-size:16px;font-weight:800;line-height:1.3;
  overflow:hidden;text-overflow:ellipsis;
}
.mb-rv-dlabel .katex{font-size:1em}
.mb-rv-dtrack{flex:1;min-width:40px;background:rgba(255,255,255,.07);border-radius:6px}
.mb-rv-dbar{height:22px;border-radius:6px;transition:width .5s}
.mb-rv-dnum{min-width:62px;text-align:right;font-size:16px;font-weight:900;white-space:nowrap}
.mb-rv-dnum span{font-size:12px;font-weight:700;opacity:.6}
.mb-rv-dmark{width:16px;color:#6EE7B7;font-weight:900}
.mb-rv-drow.ok .mb-rv-dlabel{text-shadow:0 0 14px rgba(110,231,183,.35)}

.mb-rv-side .rank-row{padding:8px 11px;font-size:14.5px;gap:8px}
.mb-rv-side .rank-pos{width:32px}
.mb-rv-side .rank-delta{min-width:44px;font-size:12px}
.mb-rv-side-note{margin-top:10px;font-size:11.5px;line-height:1.45;color:var(--mb-muted)}

@media (max-width:860px){
  .mb-rv-grid{grid-template-columns:1fr}
  .mb-rv-answer-val{font-size:30px}
  .mb-rv-stat b{font-size:22px}
  .mb-rv-dlabel{min-width:60px;font-size:14.5px}
  .mb-rv-dnum{min-width:52px;font-size:14.5px}
}
.mb-rv-more{font-size:12.5px;font-weight:700;color:var(--mb-muted);padding-left:2px}