:root{--ink:#163b73;--ink2:#0d2b56;--paper:#f7f4ed;--card:#fff;--line:#d9dfeb;--muted:#687386;--green:#277a4c;--amber:#a76b13;--red:#9c312a;--shadow:0 12px 34px rgba(13,43,86,.09)}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:#172033;font:14px/1.5 Inter,system-ui,-apple-system,"Segoe UI",sans-serif}.shell{max-width:1500px;margin:auto;padding:24px}.hidden{display:none!important}.brand{font-weight:800;color:var(--ink);letter-spacing:.04em;text-transform:uppercase;font-size:12px}h1,h2,h3{color:var(--ink2);margin:.25rem 0}.muted{color:var(--muted)}button,input,select{font:inherit}button{border:1px solid var(--line);background:#fff;border-radius:9px;padding:9px 12px;cursor:pointer}button:hover{border-color:#aab8ce}.primary{background:var(--ink);border-color:var(--ink);color:#fff;font-weight:700}.login-card{max-width:420px;margin:9vh auto;background:var(--card);border:1px solid var(--line);border-radius:18px;padding:28px;box-shadow:var(--shadow)}label{display:block;margin:15px 0 6px;font-weight:700}label input{display:block;width:100%;margin-top:6px;padding:11px 12px;border:1px solid var(--line);border-radius:9px}.login-card button{width:100%;margin-top:10px}.message{min-height:22px;margin-top:12px;color:var(--red)}.topbar{display:flex;justify-content:space-between;align-items:center;gap:18px;margin-bottom:18px}.top-actions{display:flex;align-items:center;gap:8px;flex-wrap:wrap}.stats{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin-bottom:14px}.stats article{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:15px 18px;box-shadow:var(--shadow)}.stats span{display:block;color:var(--muted);font-size:12px}.stats b{display:block;font-size:27px;color:var(--ink2);margin-top:3px}.toolbar{display:grid;grid-template-columns:minmax(240px,1fr) minmax(170px,260px) auto;gap:10px;align-items:center;margin-bottom:14px}.toolbar input,.toolbar select{width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:9px;background:#fff}.layout{display:grid;grid-template-columns:minmax(0,1.7fr) minmax(320px,.8fr);gap:14px}.table-card,.detail-card{background:var(--card);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow)}.table-wrap{overflow:auto;max-height:70vh}table{width:100%;border-collapse:collapse;min-width:800px}th,td{text-align:left;padding:12px;border-bottom:1px solid #edf0f5;vertical-align:top}th{position:sticky;top:0;background:#f5f7fb;color:var(--ink2);font-size:12px;z-index:1}tbody tr{cursor:pointer}tbody tr:hover{background:#f8fafc}.pill{display:inline-block;border-radius:999px;padding:3px 8px;font-size:11px;font-weight:800}.studying{background:#e5f5ec;color:var(--green)}.idle{background:#fff3dc;color:var(--amber)}.offline,.ended{background:#f0f2f5;color:#687386}.detail-card{padding:18px;max-height:70vh;overflow:auto}.detail-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:8px;margin:14px 0}.metric{border:1px solid var(--line);border-radius:10px;padding:9px}.metric span{font-size:11px;color:var(--muted);display:block}.metric b{color:var(--ink2)}.history{margin-top:15px}.history-item{border-top:1px solid #edf0f5;padding:10px 0}.history-item:first-child{border-top:0}.score{font-weight:800;color:var(--ink)}.warning{background:#fff1d6;border:1px solid #e8c77d;color:#6a4b0c;padding:11px 14px;border-radius:10px;margin-bottom:12px}.empty{padding:22px;color:var(--muted);text-align:center}.small{font-size:12px}.truncate{max-width:260px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
@media(max-width:980px){.layout{grid-template-columns:1fr}.detail-card{max-height:none}.stats{grid-template-columns:repeat(2,1fr)}.toolbar{grid-template-columns:1fr 1fr}.toolbar .muted{grid-column:1/-1}.topbar{align-items:flex-start;flex-direction:column}}
@media(max-width:560px){.shell{padding:12px}.stats{grid-template-columns:1fr 1fr}.toolbar{grid-template-columns:1fr}.toolbar .muted{grid-column:auto}.top-actions{width:100%}.top-actions .muted{width:100%}}


/* ===== Responsive upgrade v3: desktop + mobile ===== */
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body{overflow-x:hidden}
.shell,.layout,.table-card,.detail-card,.table-wrap{min-width:0;max-width:100%}
.top-actions{min-width:0}
#teacherEmail{overflow-wrap:anywhere}
.history-item,.detail-card{overflow-wrap:anywhere;word-break:break-word}

@media(max-width:720px){
  body{font-size:16px;line-height:1.55}
  .shell{width:100%;padding:12px}
  .brand{font-size:12px}
  h1{font-size:28px;line-height:1.2}
  h2{font-size:23px}
  h3{font-size:18px}

  button,input,select{font-size:16px}
  button{min-height:46px;padding:11px 14px;border-radius:11px}
  input,select{min-height:48px}

  /* Login: large, touch-friendly, no browser zoom */
  .login-card{
    width:auto;
    max-width:none;
    margin:4vh 0;
    padding:22px 18px;
    border-radius:18px
  }
  .login-card h1{font-size:30px;margin-top:6px}
  .login-card p{font-size:15px}
  .login-card label{font-size:16px;margin-top:17px}
  .login-card label input{
    min-height:50px;
    padding:13px 14px;
    font-size:16px;
    border-radius:11px
  }
  .login-card button{min-height:50px;font-size:17px}

  /* Header */
  .topbar{gap:12px;margin-bottom:14px}
  .topbar>div:first-child{width:100%}
  .top-actions{
    display:grid;
    grid-template-columns:repeat(3,minmax(0,1fr));
    width:100%;
    gap:8px
  }
  .top-actions .muted{
    grid-column:1/-1;
    width:100%;
    font-size:14px;
    line-height:1.35
  }
  .top-actions button{width:100%;padding-left:8px;padding-right:8px}

  /* Summary cards */
  .stats{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}
  .stats article{padding:14px 15px;min-height:92px}
  .stats span{font-size:13px}
  .stats b{font-size:30px}

  /* Filters */
  .toolbar{grid-template-columns:1fr;gap:9px}
  .toolbar input,.toolbar select{padding:12px 13px;font-size:16px}
  .toolbar .muted{font-size:13px}

  /* Important: prevent the 800px desktop table from shrinking the whole page */
  .layout{display:block}
  .table-card{width:100%;overflow:hidden}
  .table-wrap{overflow:visible;max-height:none;width:100%}
  table{display:block;width:100%;min-width:0}
  thead{display:none}
  tbody{display:block;width:100%}

  /* Student table becomes touch-friendly cards */
  tbody tr{
    display:grid;
    grid-template-columns:minmax(0,1fr) minmax(0,1fr);
    gap:10px 12px;
    width:auto;
    margin:10px;
    padding:14px;
    border:1px solid var(--line);
    border-radius:14px;
    background:#fff;
    box-shadow:0 5px 18px rgba(13,43,86,.06)
  }
  tbody tr:hover{background:#fff}
  tbody td{
    display:block;
    min-width:0;
    padding:0;
    border:0;
    font-size:14px;
    line-height:1.4;
    overflow-wrap:anywhere
  }
  tbody td::before{
    display:block;
    margin-bottom:2px;
    color:var(--muted);
    font-size:11px;
    line-height:1.2;
    font-weight:700;
    text-transform:none
  }
  tbody td:nth-child(1){grid-column:1/-1;font-size:18px;font-weight:800;color:var(--ink2)}
  tbody td:nth-child(1)::before{content:"Học viên"}
  tbody td:nth-child(2)::before{content:"Lớp"}
  tbody td:nth-child(3){grid-column:1/-1;font-size:15px}
  tbody td:nth-child(3)::before{content:"Bài gần nhất"}
  tbody td:nth-child(4)::before{content:"Hoạt động cuối"}
  tbody td:nth-child(5)::before{content:"Trạng thái"}
  tbody td:nth-child(6)::before{content:"Điểm gần nhất"}
  .truncate{
    max-width:none;
    white-space:normal;
    overflow:visible;
    text-overflow:clip
  }
  .pill{font-size:12px;padding:4px 9px}

  /* Student detail */
  .detail-card{
    width:100%;
    margin-top:12px;
    padding:16px;
    max-height:none
  }
  .detail-card>h2{font-size:24px}
  .detail-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:9px}
  .metric{padding:10px;min-width:0}
  .metric span{font-size:12px}
  .metric b{font-size:15px;overflow-wrap:anywhere}
  .history{margin-top:18px}
  .history h3{font-size:18px}
  .history-item{font-size:14px;line-height:1.55}
  .history-item .small{font-size:13px}

  .empty{padding:20px 14px;font-size:15px}
}

@media(max-width:420px){
  .shell{padding:10px}
  h1{font-size:26px}
  .top-actions{grid-template-columns:1fr 1fr}
  .top-actions .muted{grid-column:1/-1}
  .top-actions #exportBtn{grid-column:1/-1}
  .stats article{padding:12px;min-height:88px}
  .stats b{font-size:28px}
  tbody tr{margin:8px;padding:13px}
  .detail-grid{grid-template-columns:1fr 1fr}
}


/* ===== Student Alert V1: no learning activity for >= 5 days ===== */
.stats{grid-template-columns:repeat(5,minmax(0,1fr))}
.alert-stat{border-color:#e7c172!important;background:#fffaf0!important}
.alert-stat span{color:#8a5b08!important}.alert-stat b{color:#a35f00!important}
.alert-panel{background:#fff;border:1px solid #e7c172;border-radius:14px;box-shadow:var(--shadow);margin-bottom:14px;overflow:hidden}
.alert-head{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:14px 16px;background:#fffaf0;border-bottom:1px solid #f0dfba}
.alert-head h2{font-size:17px;margin:0 0 2px;color:#7a4d00}
.alert-count{display:inline-flex;align-items:center;justify-content:center;white-space:nowrap;border-radius:999px;padding:5px 10px;background:#f4dfb2;color:#744800;font-size:12px;font-weight:800}
.alert-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0}
.alert-item{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:8px 12px;padding:13px 16px;border-bottom:1px solid #f0f1f4;cursor:pointer;min-width:0}
.alert-item:nth-child(odd){border-right:1px solid #f0f1f4}.alert-item:hover{background:#fffdf8}
.alert-item.no-link{cursor:default}.alert-name{font-weight:800;color:var(--ink2);min-width:0;overflow-wrap:anywhere}.alert-meta{font-size:12px;color:var(--muted);margin-top:2px;overflow-wrap:anywhere}
.alert-days{align-self:start;border-radius:999px;padding:4px 8px;background:#fff0d5;color:#9a5a00;font-size:11px;font-weight:800;white-space:nowrap}
.alert-last{grid-column:1/-1;font-size:12px;color:#745f42}.alert-ok{padding:15px 16px;color:var(--green);font-weight:700;background:#f7fcf9}
@media(max-width:1100px){.stats{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media(max-width:720px){.stats{grid-template-columns:repeat(2,minmax(0,1fr))}.alert-list{grid-template-columns:1fr}.alert-item:nth-child(odd){border-right:0}.alert-head{align-items:flex-start;flex-direction:column}.alert-count{align-self:flex-start}}

/* Alert collapse / expand */
.alert-actions{display:flex;align-items:center;gap:8px;flex-wrap:wrap;justify-content:flex-end}
.alert-toggle{border:1px solid #dfc68f;background:#fff;color:#744800;border-radius:9px;padding:6px 10px;font-size:12px;font-weight:800;white-space:nowrap}
.alert-toggle:hover{background:#fff7e8;border-color:#c99b46}
.alert-panel.alert-collapsed .alert-list{display:none}
.alert-panel.alert-collapsed .alert-head{border-bottom:0}
@media(max-width:720px){.alert-actions{width:100%;justify-content:flex-start}.alert-toggle{padding:6px 9px}}


/* ===== Teacher Dashboard V5 · 20260904-teacher-export-v5-3 ===== */
.view-tabs{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin:0 0 14px}
.view-tab{border:1px solid var(--line);background:#fff;color:var(--ink2);font-weight:800;padding:9px 15px}
.view-tab.active{background:var(--ink);border-color:var(--ink);color:#fff}
.refresh-stamp{margin-left:auto;font-size:12px}
.placement-stats{grid-template-columns:repeat(3,minmax(0,1fr));max-width:820px}
.placement-toolbar{grid-template-columns:minmax(240px,1fr) minmax(170px,260px) auto}
#placementTable{min-width:720px}
#placementTable tbody tr{cursor:pointer}
#placementTable .score{white-space:nowrap}
@media(max-width:720px){
  .view-tabs{display:grid;grid-template-columns:1fr 1fr;gap:8px}
  .view-tab{width:100%;min-height:46px}
  .refresh-stamp{grid-column:1/-1;margin-left:0}
  .placement-stats{grid-template-columns:repeat(3,minmax(0,1fr));max-width:none}
  .placement-toolbar{grid-template-columns:1fr}
  #placementTable{min-width:0}
  #placementTable tbody td:nth-child(1)::before{content:"Họ tên"}
  #placementTable tbody td:nth-child(2)::before{content:"HSK"}
  #placementTable tbody td:nth-child(3)::before{content:"Đề"}
  #placementTable tbody td:nth-child(4)::before{content:"Thời gian"}
  #placementTable tbody td:nth-child(5)::before{content:"Điểm"}
  #placementTable tbody td:nth-child(6)::before{content:"Đúng / Tổng"}
}
@media(max-width:560px){
  .placement-stats{grid-template-columns:1fr 1fr}
  .placement-stats article:first-child{grid-column:1/-1}
}


/* ===== Teacher Dashboard V5.2 · Essay viewer · 20260904 ===== */
.essay-view-btn{margin-top:10px;padding:7px 11px;border:1px solid #b9c9df;border-radius:9px;background:#f5f8fc;color:var(--ink);font-size:12px;font-weight:800;cursor:pointer}
.essay-view-btn:hover{background:#eaf1fa;border-color:#8fa8c8}
body.essay-open{overflow:hidden}
.essay-modal{position:fixed;inset:0;z-index:9999;display:flex;align-items:center;justify-content:center;padding:18px}
.essay-modal.hidden{display:none!important}
.essay-backdrop{position:absolute;inset:0;background:rgba(12,31,57,.48);backdrop-filter:blur(2px)}
.essay-dialog{position:relative;width:min(760px,100%);max-height:calc(100vh - 36px);overflow:auto;background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:0 24px 70px rgba(12,31,57,.28);padding:20px}
.essay-head{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;margin-bottom:8px}
.essay-head h2{margin:3px 0 0;font-size:24px;color:var(--ink2)}
.essay-close{flex:0 0 auto;border:1px solid var(--line);background:#fff;color:var(--ink2);font-weight:800;padding:8px 12px;border-radius:9px}
.essay-close:hover{background:#f6f8fb}
.essay-meta{font-size:13px;line-height:1.5;padding-bottom:12px;border-bottom:1px solid var(--line)}
.essay-body{margin-top:14px;padding:16px;border-radius:12px;background:#f8fafc;border:1px solid #e3e9f1;color:var(--ink2);font-size:16px;line-height:1.75;white-space:pre-wrap;overflow-wrap:anywhere;word-break:break-word}
@media(max-width:560px){.essay-modal{padding:8px;align-items:flex-end}.essay-dialog{width:100%;max-height:92vh;border-radius:16px 16px 10px 10px;padding:16px}.essay-head h2{font-size:21px}.essay-body{font-size:16px;padding:13px}.essay-view-btn{width:100%;min-height:42px;font-size:14px}}


/* ===== Teacher Dashboard V5.3 · filtered grading export ===== */
.detail-actions{display:flex;gap:8px;flex-wrap:wrap;margin:12px 0 4px}.detail-export-btn{background:var(--ink);border-color:var(--ink);color:#fff;font-weight:800}.detail-secondary-btn{font-weight:700;background:#f8fafc}
body.export-open{overflow:hidden}.export-modal{position:fixed;inset:0;z-index:10020;display:flex;align-items:center;justify-content:center;padding:18px}.export-modal.hidden{display:none!important}.export-backdrop{position:absolute;inset:0;background:rgba(12,31,57,.52);backdrop-filter:blur(2px)}.export-dialog{position:relative;width:min(920px,100%);max-height:calc(100vh - 36px);overflow:auto;background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:0 24px 70px rgba(12,31,57,.30);padding:22px}.export-head{display:flex;align-items:flex-start;justify-content:space-between;gap:16px}.export-head h2{font-size:24px;margin:3px 0 0}.export-close{font-weight:800}.export-note{margin:8px 0 16px}.export-grid,.export-date-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.export-grid label,.export-date-grid label{margin:0}.export-grid select,.export-date-grid input,.export-search{width:100%;margin-top:6px;padding:10px 11px;border:1px solid var(--line);border-radius:9px;background:#fff}.export-date-grid{margin-top:10px}.export-lessons-head{display:flex;justify-content:space-between;align-items:flex-end;gap:12px;margin-top:18px}.export-mini-actions{display:flex;gap:7px}.export-mini-actions button{padding:7px 10px;font-size:12px}.export-search{margin-top:9px}.export-lesson-list{margin-top:8px;border:1px solid var(--line);border-radius:12px;max-height:270px;overflow:auto;background:#fbfcfe}.export-lesson-item{display:grid;grid-template-columns:auto 1fr auto;align-items:start;gap:9px;margin:0;padding:9px 11px;border-bottom:1px solid #edf0f5;font-weight:600}.export-lesson-item:last-child{border-bottom:0}.export-lesson-item input{margin-top:3px}.export-lesson-item small{color:var(--muted);font-weight:500;white-space:nowrap}.export-no-lessons{padding:14px}.export-check{display:flex;align-items:flex-start;gap:8px;margin:13px 0 0;font-weight:700}.export-check input{margin-top:4px}.export-writing-rule{margin-top:12px;background:#f4f8fd;border:1px solid #d6e1ef;border-radius:10px;padding:11px 12px;color:var(--ink2)}.export-summary{margin-top:12px;padding:10px 12px;background:#faf8f1;border:1px solid #eadcb3;border-radius:9px}.export-actions{display:flex;justify-content:flex-end;gap:9px;flex-wrap:wrap;margin-top:16px}.export-actions button{font-weight:800}
@media(max-width:650px){.detail-actions{display:grid;grid-template-columns:1fr}.detail-actions button{width:100%}.export-modal{padding:7px;align-items:flex-end}.export-dialog{width:100%;max-height:94vh;border-radius:16px 16px 9px 9px;padding:15px}.export-grid,.export-date-grid{grid-template-columns:1fr}.export-lessons-head{align-items:flex-start;flex-direction:column}.export-mini-actions{width:100%}.export-mini-actions button{flex:1}.export-actions{display:grid;grid-template-columns:1fr}.export-actions button{width:100%;min-height:44px}.export-head h2{font-size:21px}.export-lesson-list{max-height:240px}}


/* ===== Teacher Dashboard V5.3.2 · source by lesson_file · 20260904-teacher-source-v5-3-2 ===== */
.source-path{margin-top:3px;max-width:100%;font-family:ui-monospace,SFMono-Regular,Consolas,monospace;font-size:11px!important;line-height:1.35;overflow-wrap:anywhere}
.lesson-source-link{color:#526f98;text-decoration:none;border-bottom:1px dotted #9fb0c8}
.lesson-source-link:hover{color:var(--ink);border-bottom-color:var(--ink)}
.export-lesson-copy{display:flex;flex-direction:column;min-width:0;gap:2px}
.export-lesson-path{display:block;color:var(--muted);font-family:ui-monospace,SFMono-Regular,Consolas,monospace;font-size:10px;line-height:1.35;overflow-wrap:anywhere}
@media(max-width:720px){
  .source-path{font-size:10px!important}
}


/* ===== Teacher Dashboard V5.4 · scored + non-scored export · 20260904-teacher-export-v5-4-activity ===== */
.export-activity-check span{display:flex;flex-direction:column;gap:2px}
.export-activity-check small{display:block;color:var(--muted);font-weight:500;line-height:1.4}


/* ===== Teacher Dashboard V5.4.1 · Search lớp/học viên · 20260904-teacher-v5-4-1-search-class-student ===== */
.export-filter-field{display:flex;flex-direction:column;min-width:0}
.export-filter-search{width:100%;margin-top:6px;padding:10px 11px;border:1px solid var(--line);border-radius:9px;background:#fff}
.export-filter-field select{margin-top:6px}
.export-filter-search:focus{outline:2px solid rgba(34,91,161,.18);outline-offset:1px;border-color:#86a7d0}
@media(max-width:650px){
  .export-filter-search{min-height:44px;font-size:16px}
  .export-filter-field select{min-height:44px;font-size:16px}
}


/* ===== WenQing Teacher 20260906-teacher-v5-5-test-tabs-permissions: 3 tabs + test detail/essay ===== */
.periodic-toolbar{grid-template-columns:minmax(240px,1fr) minmax(170px,240px) minmax(150px,220px);margin-bottom:8px}
.test-mode-note{margin:0 0 14px 2px}
#placementTable{min-width:1080px}
#periodicTable{min-width:1260px}
.test-detail-preview{max-width:260px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;color:var(--ink2)}
.test-detail-full{white-space:pre-wrap;overflow-wrap:anywhere;line-height:1.65}
#placementRows .essay-view-btn,#periodicRows .essay-view-btn{white-space:nowrap}

@media (max-width:760px){
  .view-tabs{display:flex;flex-wrap:nowrap;overflow-x:auto;-webkit-overflow-scrolling:touch;gap:8px;padding-bottom:3px}
  .view-tab{width:auto;min-height:44px;flex:0 0 auto;white-space:nowrap}
  .refresh-stamp{flex:0 0 auto;align-self:center}
  .periodic-toolbar{grid-template-columns:1fr}
  #placementTable,#periodicTable{min-width:0}
  #placementTable tbody td:nth-child(1)::before{content:"Họ tên"}
  #placementTable tbody td:nth-child(2)::before{content:"HSK"}
  #placementTable tbody td:nth-child(3)::before{content:"Đề"}
  #placementTable tbody td:nth-child(4)::before{content:"Thời gian"}
  #placementTable tbody td:nth-child(5)::before{content:"Điểm"}
  #placementTable tbody td:nth-child(6)::before{content:"Đúng / Tổng"}
  #placementTable tbody td:nth-child(7)::before{content:"Câu sai / Đáp án đúng"}
  #placementTable tbody td:nth-child(8)::before{content:"Phần viết"}
  #periodicTable tbody td:nth-child(1)::before{content:"Học viên"}
  #periodicTable tbody td:nth-child(2)::before{content:"Lớp"}
  #periodicTable tbody td:nth-child(3)::before{content:"HSK"}
  #periodicTable tbody td:nth-child(4)::before{content:"Đề"}
  #periodicTable tbody td:nth-child(5)::before{content:"Thời gian"}
  #periodicTable tbody td:nth-child(6)::before{content:"Điểm"}
  #periodicTable tbody td:nth-child(7)::before{content:"Đúng / Tổng"}
  #periodicTable tbody td:nth-child(8)::before{content:"Câu sai / Đáp án đúng"}
  #periodicTable tbody td:nth-child(9)::before{content:"Phần viết"}
  .test-detail-preview{max-width:none;white-space:normal;overflow:visible;text-overflow:clip}
}

/* ===== Teacher v5.6 · Học liệu bổ sung ===== */
.material-stats{grid-template-columns:repeat(5,minmax(0,1fr))}
.material-toolbar{grid-template-columns:minmax(240px,1fr) minmax(170px,240px) minmax(210px,320px);margin-bottom:8px}
#materialTable{min-width:1120px}
.material-guest-stat{border-color:#b9cbe1!important;background:#f7fbff!important}
.material-guest-stat span{color:#4a6281!important}.material-guest-stat b{color:var(--ink)!important}
.material-guest-panel{background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow);margin:14px 0;overflow:hidden}
.material-guest-head{padding:14px 16px;background:#f7fbff;border-bottom:1px solid #e5ecf5}.material-guest-head h2{font-size:17px;margin:0 0 2px}
.material-guest-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:0}
.material-guest-card{padding:14px 16px;border-right:1px solid #edf0f5;min-width:0}.material-guest-card:last-child{border-right:0}
.material-guest-card b{display:block;color:var(--ink2);font-size:15px;margin-bottom:5px}.material-guest-card span{display:block;color:var(--muted);font-size:12px}.material-guest-card strong{color:var(--ink);font-size:20px}
.material-progress{font-weight:800;color:var(--ink2)}
.material-kind{font-size:11px;color:var(--muted);margin-top:3px}
.material-detail-path{margin-top:3px}
@media(max-width:1100px){.material-stats{grid-template-columns:repeat(3,minmax(0,1fr))}.material-guest-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.material-guest-card:nth-child(2){border-right:0}.material-guest-card:nth-child(-n+2){border-bottom:1px solid #edf0f5}}
@media(max-width:760px){
  .material-toolbar{grid-template-columns:1fr}
  #materialTable{min-width:0}
  .material-guest-grid{grid-template-columns:1fr}.material-guest-card{border-right:0;border-bottom:1px solid #edf0f5}.material-guest-card:last-child{border-bottom:0}
  #materialTable tbody td:nth-child(1)::before{content:"Học viên"}
  #materialTable tbody td:nth-child(2)::before{content:"Lớp"}
  #materialTable tbody td:nth-child(3)::before{content:"Học liệu"}
  #materialTable tbody td:nth-child(4)::before{content:"Tiến độ / Phần gần nhất"}
  #materialTable tbody td:nth-child(5)::before{content:"Lần cuối"}
  #materialTable tbody td:nth-child(6)::before{content:"Số phiên"}
  #materialTable tbody td:nth-child(7)::before{content:"Thời lượng"}
  #materialTable tbody td:nth-child(3),#materialTable tbody td:nth-child(4){grid-column:1/-1}
}
@media(max-width:560px){.material-stats{grid-template-columns:1fr 1fr}.material-stats article:first-child{grid-column:1/-1}}

/* ===== Teacher Dashboard V5.8 · Tài khoản giáo viên · 20260923 ===== */
.admin-head{display:flex;align-items:flex-start;justify-content:space-between;gap:12px;margin:14px 0}.admin-head h2{margin:0 0 3px}.teacher-admin-layout{display:grid;grid-template-columns:minmax(0,1.45fr) minmax(320px,.85fr);gap:14px;align-items:start}#teacherAdminTable{min-width:840px}.teacher-admin-class-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:7px;margin-top:10px}.teacher-admin-class{display:flex;align-items:center;gap:7px;padding:8px 9px;border:1px solid var(--line);border-radius:9px;background:#fbfcfe;font-weight:650}.teacher-admin-class input{width:auto;margin:0}.teacher-admin-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px}.teacher-admin-actions button{font-weight:800}.teacher-admin-danger{border-color:#e2b9b9!important;color:#9b2f2f!important;background:#fff8f8!important}.teacher-admin-section{margin-top:16px;padding-top:14px;border-top:1px solid var(--line)}.teacher-admin-section h3{margin:0 0 8px}.teacher-admin-password{display:grid;grid-template-columns:1fr auto;gap:8px;align-items:end}.teacher-admin-password label{margin:0}.teacher-admin-password input{width:100%;margin-top:6px;padding:10px 11px;border:1px solid var(--line);border-radius:9px}.teacher-admin-badge{display:inline-block;padding:3px 7px;border-radius:999px;font-size:11px;font-weight:800;background:#edf3fb;color:#385a82}.teacher-admin-badge.off{background:#f4eeee;color:#855}.teacher-admin-row-active{cursor:pointer}.teacher-admin-row-active:hover{background:#f8fbff}.teacher-admin-note{margin-top:10px;padding:10px 12px;border:1px solid #e7d9ae;background:#fffaf0;border-radius:9px;line-height:1.5}
@media(max-width:900px){.teacher-admin-layout{grid-template-columns:1fr}.teacher-admin-class-list{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media(max-width:760px){.admin-head{flex-direction:column}.admin-head button{width:100%}.teacher-admin-class-list{grid-template-columns:1fr 1fr}#teacherAdminTable{min-width:0}#teacherAdminTable tbody td:nth-child(1)::before{content:"Giáo viên"}#teacherAdminTable tbody td:nth-child(2)::before{content:"Email"}#teacherAdminTable tbody td:nth-child(3)::before{content:"Vai trò"}#teacherAdminTable tbody td:nth-child(4)::before{content:"Trạng thái"}#teacherAdminTable tbody td:nth-child(5)::before{content:"Lớp phụ trách"}.teacher-admin-password{grid-template-columns:1fr}.teacher-admin-password button{width:100%;min-height:44px}}

/* ===== V5.8 account-only admin refinements ===== */
.teacher-admin-badge.ok{background:#edf8f1;color:#28643d}
.teacher-admin-badge.warn{background:#fff6df;color:#8a6412}
.teacher-admin-account-line{margin-top:10px;display:flex;align-items:center;gap:7px;flex-wrap:wrap}
.teacher-admin-class-readonly-list{display:flex;flex-wrap:wrap;gap:7px;margin-top:10px}
.teacher-admin-class-readonly{display:inline-flex;align-items:center;padding:7px 9px;border:1px solid var(--line);border-radius:999px;background:#f7f9fc;font-weight:700;font-size:12px;color:var(--ink2)}
@media(max-width:760px){
  #teacherAdminTable tbody td:nth-child(1)::before{content:"Giáo viên"}
  #teacherAdminTable tbody td:nth-child(2)::before{content:"Email"}
  #teacherAdminTable tbody td:nth-child(3)::before{content:"Hồ sơ"}
  #teacherAdminTable tbody td:nth-child(4)::before{content:"Tài khoản"}
  #teacherAdminTable tbody td:nth-child(5)::before{content:"Lớp phụ trách"}
}

/* ===== Teacher Dashboard V6 · WenQing brand + Vietnamese UI + class admin · 20261001 ===== */
:root{
  --ink:#013992;
  --ink2:#082f70;
  --paper:#f4f7fb;
  --card:#ffffff;
  --line:#d6e1ef;
  --muted:#66758a;
  --green:#237648;
  --amber:#9b6818;
  --red:#a33232;
  --shadow:0 10px 30px rgba(8,47,112,.08)
}
body{background:linear-gradient(180deg,#f8fbff 0,#f4f7fb 220px,#f4f7fb 100%)}
.shell{max-width:1540px}
.brand{color:var(--ink);letter-spacing:.065em}
.brand-sub{font-size:12px;color:var(--muted);font-weight:700;margin-top:2px}
.brand-logo{display:block;object-fit:contain;flex:0 0 auto}
.login-branding,.header-brand{display:flex;align-items:center;gap:14px;min-width:0}
.login-logo{width:68px;height:68px}
.header-logo{width:56px;height:56px}
.header-brand h1{margin:.08rem 0 0}
.header-welcome{margin-top:3px;color:#4f6480;font-size:13px;font-weight:650}
.teacher-email{font-size:13px}
.login-card{max-width:460px;border-color:#cfdaea;padding:30px 32px;background:rgba(255,255,255,.97)}
.login-card h1{margin-top:18px;font-size:30px}
.login-card label input:focus,.toolbar input:focus,.toolbar select:focus,.teacher-admin-password input:focus,.class-danger-zone input:focus{outline:3px solid rgba(1,57,146,.12);border-color:#6f98cf}
.primary{background:var(--ink);border-color:var(--ink)}
.primary:hover{background:#002f79;border-color:#002f79}
.topbar{padding:4px 0 2px}
.view-tabs{gap:9px;align-items:center}
.view-tab{font-weight:750;color:#123b72;background:#fff}
.view-tab.active{background:var(--ink);border-color:var(--ink);color:#fff;box-shadow:0 5px 14px rgba(1,57,146,.14)}
.admin-tab{border-style:dashed}
.stats{grid-template-columns:repeat(4,minmax(0,1fr))}
.stats article{border-color:#d3dfed;box-shadow:0 8px 22px rgba(8,47,112,.06)}
.stats b{color:var(--ink)}
.toolbar{position:relative}
.search-autocomplete{position:relative;min-width:0}
.search-suggestions{position:absolute;z-index:30;left:0;right:0;top:calc(100% + 6px);background:#fff;border:1px solid #cbd9ea;border-radius:12px;box-shadow:0 18px 38px rgba(8,47,112,.16);overflow:hidden;max-height:390px;overflow-y:auto}
.search-suggestion{display:grid;width:100%;grid-template-columns:78px minmax(0,1fr);gap:2px 10px;align-items:center;text-align:left;border:0;border-bottom:1px solid #edf2f7;border-radius:0;padding:10px 12px;background:#fff;min-height:0}
.search-suggestion:last-child{border-bottom:0}.search-suggestion:hover{background:#f4f8fd}
.search-suggestion .suggestion-kind{grid-row:1/3;color:#68809f;font-size:11px;font-weight:800;text-transform:uppercase;letter-spacing:.03em}
.search-suggestion b{color:var(--ink2);font-size:14px;overflow-wrap:anywhere}.search-suggestion small{color:var(--muted);overflow-wrap:anywhere}
.search-suggestion-empty{padding:13px;color:var(--muted);font-size:13px}
.pill.studying{background:#e8f6ee;color:#1f7445}.pill.idle{background:#fff3d9;color:#8b6118}.pill.offline,.pill.ended{background:#eef2f7;color:#66758a}
.class-admin-toolbar{display:grid;grid-template-columns:minmax(220px,1fr) minmax(180px,260px) auto;gap:10px;align-items:center;margin:8px 0 14px}.class-admin-toolbar input,.class-admin-toolbar select{width:100%;min-height:44px;padding:10px 12px;border:1px solid var(--line);border-radius:10px;background:#fff;color:var(--ink2)}.class-admin-toolbar input:focus,.class-admin-toolbar select:focus{outline:2px solid rgba(16,76,162,.16);border-color:#89a9d5}.class-admin-toolbar #classAdminFilterInfo{white-space:nowrap;text-align:right}
.class-admin-layout{display:grid;grid-template-columns:minmax(0,1.45fr) minmax(320px,.85fr);gap:14px;align-items:start}
#classAdminTable{min-width:760px}.class-admin-row{cursor:pointer}.class-admin-row:hover{background:#f7faff}
.class-danger-zone{margin-top:18px;padding:15px;border:1px solid #e5bbbb;border-radius:12px;background:#fff9f9}
.class-danger-zone h3{margin:0 0 6px;color:#8f2f2f}.class-danger-zone p{margin:0 0 10px}.class-danger-zone label{margin:8px 0 10px}.class-danger-zone input{width:100%;margin-top:6px;padding:10px 11px;border:1px solid #dccaca;border-radius:9px;background:#fff}
.class-danger-zone button{font-weight:800}

@media(max-width:980px){.class-admin-layout{grid-template-columns:1fr}.class-admin-toolbar{grid-template-columns:1fr 220px}.class-admin-toolbar #classAdminFilterInfo{grid-column:1/-1;text-align:left}}
@media(max-width:760px){
  body{background:#f5f8fc}
  .class-admin-toolbar{grid-template-columns:1fr}.class-admin-toolbar #classAdminFilterInfo{grid-column:auto;text-align:left}
  .login-card{margin:3vh 0;padding:22px 18px}.login-logo{width:60px;height:60px}.login-card h1{font-size:27px}
  .header-logo{width:46px;height:46px}.header-brand{gap:11px}.header-brand h1{font-size:27px}.header-welcome{font-size:13px}
  .top-actions{grid-template-columns:repeat(3,minmax(0,1fr))}
  .view-tabs{scroll-snap-type:x proximity;padding:2px 2px 7px;margin-left:-2px;margin-right:-2px}
  .view-tab{scroll-snap-align:start}
  .stats{grid-template-columns:repeat(2,minmax(0,1fr))}
  .search-suggestions{position:fixed;left:12px;right:12px;top:auto;max-height:46vh}
  #classAdminTable{min-width:0}
  #classAdminTable tbody td:nth-child(1)::before{content:"Mã lớp"}
  #classAdminTable tbody td:nth-child(2)::before{content:"Đang học"}
  #classAdminTable tbody td:nth-child(3)::before{content:"Hồ sơ LMS"}
  #classAdminTable tbody td:nth-child(4)::before{content:"Phiên học"}
  #classAdminTable tbody td:nth-child(5)::before{content:"Kết quả"}
  #classAdminTable tbody td:nth-child(6)::before{content:"Trạng thái"}
  #classAdminTable tbody td:nth-child(1){grid-column:1/-1}
}
@media(max-width:420px){
  .login-branding{gap:10px}.login-logo{width:54px;height:54px}
  .header-logo{width:42px;height:42px}.header-brand h1{font-size:24px}
}

.center-link{display:inline-flex;align-items:center;text-decoration:none;padding:10px 14px;border-radius:10px;background:#eef4fb;color:#163b73;font-weight:700;border:1px solid #cbd8e8}.center-link.hidden{display:none!important}

/* Teacher V5 — high contrast, readable learning and unsent-exam statuses. */
#studentRows .pill.studying,.wq-live-exam-row .pill.studying{background:#d2f5df!important;color:#11623e!important;border:1px solid #52b881}
#studentRows .pill.idle,.wq-live-exam-row .pill.idle{background:#fff0be!important;color:#855200!important;border:1px solid #dfbf63}
.wq-live-exam-row{background:#f8fcff}
.wq-live-exam-row:hover{background:#effaf3}
.wq-live-exam-row .pill{display:inline-flex;margin-top:5px;align-items:center;white-space:nowrap}
.pill.wq-submitted{background:#e8f0ff;color:#1f4d93;margin-top:5px}
.wq-live-progress{color:#164878;font-size:12px}
.wq-live-metric{border-color:#abd9b7!important;background:#f0fbf4!important}
.wq-live-metric b{color:#127647!important}
.wq-paused-metric{border-color:#ead3a4!important;background:#fffaf0!important}
.wq-paused-metric b{color:#95610f!important}
/* Stronger summary numbers without confusing a pause with a live session. */
#statStudying{color:#13834d!important}
#statIdle{color:#9b6b16!important}