/* Layout: full-height app shell — navy sidebar on the left, scrolling work area on the right. No marketing header/footer. */
:root{
  color-scheme:light;
  --bg:#F3F6F9; --surface:#FFFFFF; --ink:#0F2A44; --muted:#4A5D72; --line:#D5DEE8;
  --chalk:#FFC93C; --chalk-ink:#0F2A44; --accent-ink:#8A5A00;
  --focus:#2F6FB3;
  --side:#2B3A57; --side-muted:#B8C4D6;
  --st-present:#1F7A4D; --st-present-bg:#E3F4EA; --st-present-solid:#2E7D4F;
  --st-late:#8F5400; --st-late-bg:#FCF0D9; --st-late-solid:#9A6212;
  --st-excused:#5444B8; --st-excused-bg:#ECEAFB; --st-excused-solid:#5B4BC4;
  --st-absent:#B42318; --st-absent-bg:#FDE8E6; --st-absent-solid:#C0392B;
  --f-body:"Be Vietnam Pro", "Segoe UI", system-ui, -apple-system, sans-serif;
}
*{box-sizing:border-box}
[hidden]{display:none!important}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--f-body);font-size:16px;line-height:1.6}
a{color:var(--accent-ink)}
:focus-visible{outline:3px solid var(--focus);outline-offset:2px}
h1,h2,h3{line-height:1.25;text-wrap:balance;margin:0}

/* controls */
.btn{appearance:none;border:0;border-radius:10px;background:var(--chalk);color:var(--chalk-ink);font:inherit;font-weight:700;font-size:15px;padding:10px 16px;min-height:44px;cursor:pointer;display:inline-flex;align-items:center;justify-content:center;gap:8px;text-decoration:none}
.btn:hover{filter:brightness(1.05)}
.btn:disabled{opacity:.55;cursor:not-allowed}
.btn.ghost{background:transparent;color:var(--ink);border:1.5px solid var(--line)}
.btn.ghost:hover{border-color:var(--ink)}
.btn.sm{min-height:36px;padding:6px 12px;font-size:14px}
.btn.danger{border-color:var(--st-absent);color:var(--st-absent)}
label.f{display:grid;gap:6px;font-weight:600;font-size:14px;color:var(--ink)}
label.f small{font-weight:400;color:var(--muted)}
input[type=text],input[type=date],input[type=time],select,textarea{font:inherit;font-size:15px;color:var(--ink);background:var(--surface);border:1.5px solid var(--line);border-radius:10px;padding:10px 12px;width:100%;min-height:44px}
select{appearance:none;-webkit-appearance:none;padding-right:42px;cursor:pointer;
  background-image:linear-gradient(45deg,transparent 50%,var(--muted) 50%),linear-gradient(135deg,var(--muted) 50%,transparent 50%);
  background-position:calc(100% - 20px) 52%,calc(100% - 14px) 52%;background-size:6px 6px,6px 6px;background-repeat:no-repeat}
select:hover{border-color:var(--muted)}
textarea{resize:vertical;line-height:1.5}
input:focus,select:focus,textarea:focus{border-color:var(--focus);outline:none;box-shadow:0 0 0 3px color-mix(in srgb,var(--focus) 25%,transparent)}
.row{display:flex;gap:12px;flex-wrap:wrap;align-items:center}
.hint{font-size:14px;color:var(--muted);margin:0}
.status{font-size:14px;color:var(--muted);min-height:1.5em;margin:0}
.muted{color:var(--muted)}

/* shell */
.shell{display:grid;grid-template-columns:252px minmax(0,1fr);min-height:100vh;min-height:100dvh}
.app-side{background:var(--side);color:#FFFFFF;padding:20px 12px;display:flex;flex-direction:column;gap:6px;position:sticky;top:0;height:100vh;height:100dvh;overflow-y:auto}
.side-brand{display:flex;align-items:center;gap:10px;padding:4px 10px 20px}
.side-brand img{width:42px;height:42px;flex:none;display:block;object-fit:contain}
.side-brand b{display:block;font-size:19px;font-weight:800;line-height:1.2}
.side-brand small{display:inline-block;margin-top:2px;font-size:11px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--chalk-ink);background:var(--chalk);border-radius:999px;padding:1px 8px}
.side-b{appearance:none;border:0;background:transparent;color:var(--side-muted);font:inherit;font-weight:600;font-size:16px;display:flex;gap:12px;align-items:center;padding:12px;border-radius:10px;min-height:48px;cursor:pointer;text-align:left}
.side-b:hover{color:#FFFFFF}
.side-b.on{background:rgba(255,255,255,.12);color:#FFFFFF}
.side-b svg{flex:none}
.side-foot{margin-top:auto;padding:16px 10px 4px;font-size:13px;color:var(--side-muted);display:grid;gap:10px}
.side-reset{appearance:none;background:transparent;border:1px solid rgba(255,255,255,.28);color:#FFFFFF;font:inherit;font-size:13px;font-weight:600;border-radius:8px;padding:8px 10px;min-height:40px;cursor:pointer;text-align:left}
.side-home{color:var(--side-muted);text-decoration:none;font-weight:600}
.side-home:hover{color:#FFFFFF}

.app-main{min-width:0;display:grid;gap:18px;align-content:start;padding:28px clamp(16px,3vw,40px) 56px;max-width:1280px;width:100%}
.app-main > *{min-width:0}
.app-top{display:flex;justify-content:space-between;align-items:flex-end;gap:12px;flex-wrap:wrap}
.app-top .d{font-size:13px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.app-top h1{font-size:clamp(26px,3.4vw,36px);font-weight:800;letter-spacing:-.01em}
.saved{font-size:14px;color:var(--muted);display:flex;gap:8px;align-items:center}
.saved i{width:9px;height:9px;border-radius:50%;background:var(--st-present-solid)}
.saved i.warn{background:var(--st-late-solid)}

/* cards & tables */
.box{background:var(--surface);border:1.5px solid var(--line);border-radius:16px;min-width:0;overflow:hidden}
.box.pad{padding:20px;display:grid;gap:12px;align-content:start}
.box h3{font-size:17px;font-weight:700}
.box-h{display:flex;gap:16px;align-items:flex-end;flex-wrap:wrap;padding:18px 20px;border-bottom:1px solid var(--line)}
.box-h label.f{min-width:150px}
.box-h .sp{margin-left:auto;display:flex;gap:8px;flex-wrap:wrap}
.box-sub{padding:16px 20px;display:grid;gap:10px;border-bottom:1px solid var(--line)}
.box-foot{padding:14px 20px;border-top:1px solid var(--line)}
.tbl-wrap{overflow-x:auto}
table{border-collapse:collapse;width:100%;min-width:720px;font-size:15px}
th,td{text-align:left;padding:10px 12px;border-bottom:1px solid var(--line);vertical-align:middle}
th{font-size:13px;font-weight:600;letter-spacing:.03em;color:var(--muted);background:var(--bg)}
tr:last-child td{border-bottom:0}
td.num{font-variant-numeric:tabular-nums;color:var(--muted);width:44px}
td.name{font-weight:600;white-space:nowrap}
td select{min-height:38px;padding:6px 38px 6px 10px;font-size:14px;width:auto;background-position:calc(100% - 18px) 52%,calc(100% - 12px) 52%}
td.out{min-width:340px;vertical-align:top}
.nx-ta{display:block;width:100%;min-height:68px;font-size:14.5px;line-height:1.55;padding:8px 10px;background:var(--bg);border:1.5px solid transparent;border-radius:10px;resize:vertical;overflow:hidden}
.nx-ta:hover{border-color:var(--line)}
.nx-ta:focus{background:var(--surface)}
.nx-ta::placeholder{color:var(--muted)}
.nx-meta{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin-top:4px;font-size:13px;min-height:32px}
.nx-tag{color:var(--st-excused);font-weight:600;display:inline-flex;align-items:center;gap:6px}
.nx-tag::before{content:"";width:6px;height:6px;border-radius:50%;background:currentColor}
.lnk{appearance:none;border:0;background:none;color:var(--accent-ink);font:inherit;font-size:13px;font-weight:700;cursor:pointer;padding:4px 0;min-height:32px}
.lnk:hover{text-decoration:underline}
table.tbl-sm{min-width:520px}
td.c,th.c{text-align:center;font-variant-numeric:tabular-nums}
td.act{white-space:nowrap;text-align:right}
.who{display:flex;gap:10px;align-items:center;font-weight:600;white-space:nowrap}
.who .av{width:34px;height:34px;font-size:12px}
.empty-state{color:var(--muted);padding:20px;margin:0;list-style:none}

.chips{display:flex;gap:8px;flex-wrap:wrap}
.chip{white-space:nowrap;display:inline-flex;align-items:center;gap:7px;font-size:14px;font-weight:600;border-radius:999px;padding:4px 12px;background:var(--bg);color:var(--muted);font-variant-numeric:tabular-nums}
.chip::before{content:"";width:7px;height:7px;border-radius:50%;background:currentColor}
.chip.present{background:var(--st-present-bg);color:var(--st-present)}
.chip.late{background:var(--st-late-bg);color:var(--st-late)}
.chip.excused{background:var(--st-excused-bg);color:var(--st-excused)}
.chip.absent{background:var(--st-absent-bg);color:var(--st-absent)}
.legend{font-size:14px;color:var(--muted);display:flex;gap:6px 18px;flex-wrap:wrap}
.legend b{color:var(--ink)}

/* điểm danh */
.dd-row{display:grid;grid-template-columns:28px 44px minmax(0,1fr) auto;gap:14px;align-items:center;padding:12px 20px;border-top:1px solid var(--line)}
#dd-rows .dd-row:first-child{border-top:0}
.dd-num{color:var(--muted);font-variant-numeric:tabular-nums}
.av{width:42px;height:42px;border-radius:50%;background:var(--bg);border:1px solid var(--line);display:grid;place-items:center;font-size:13px;font-weight:700;color:var(--muted);flex:none}
.dd-who{min-width:0}
.dd-who b{display:block;font-weight:700;font-size:17px}
.dd-who small{color:var(--muted);font-size:13px}
.seg{display:inline-flex;background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:4px;gap:2px;flex-wrap:wrap}
.seg-b{appearance:none;border:0;background:transparent;font:inherit;font-weight:600;font-size:15px;color:var(--muted);border-radius:9px;padding:8px 14px;min-height:42px;cursor:pointer}
.seg-b:hover{color:var(--ink)}
.seg-b.on{color:#FFFFFF}
.seg-b.on.present{background:var(--st-present-solid)}
.seg-b.on.late{background:var(--st-late-solid)}
.seg-b.on.excused{background:var(--st-excused-solid)}
.seg-b.on.absent{background:var(--st-absent-solid)}

/* tổng quan */
.tiles{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px}
.tile{background:var(--surface);border:1.5px solid var(--line);border-radius:14px;padding:16px 18px;display:grid;gap:4px}
.tile .k{font-size:14px;font-weight:600;color:var(--muted)}
.tile .v{font-size:34px;font-weight:800;font-variant-numeric:tabular-nums;line-height:1.1}
.tile.present .v{color:var(--st-present)} .tile.late .v{color:var(--st-late)} .tile.absent .v{color:var(--st-absent)}
.tq-grid{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(0,1fr);gap:18px}
.bars{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:10px;align-items:end;height:200px;padding-top:8px}
.bar-col{display:flex;flex-direction:column;align-items:center;justify-content:flex-end;gap:6px;height:100%;min-width:0}
.bar-col .v{font-size:13px;font-weight:700;font-variant-numeric:tabular-nums}
.bar-col .b{width:100%;max-width:44px;background:var(--st-present-solid);border-radius:6px 6px 2px 2px}
.bar-col .l{font-size:12px;color:var(--muted);text-align:center;line-height:1.3}
.flag-list{list-style:none;margin:0;padding:0;display:grid}
.flag-list li{display:grid;grid-template-columns:42px minmax(0,1fr) auto;gap:12px;align-items:center;padding:10px 0;border-top:1px solid var(--line)}
.flag-list li:first-child{border-top:0}
.flag-list .tags{display:flex;gap:6px;flex-wrap:wrap;justify-content:flex-end}

/* học sinh */
.hs-tools{display:flex;gap:12px;flex-wrap:wrap;align-items:flex-end;padding:16px 20px;border-bottom:1px solid var(--line)}
.hs-tools label.f{flex:1 1 180px}
.hs-tools .count{margin-left:auto;font-size:14px;color:var(--muted);align-self:center}
.hs-note{padding:10px 20px;border-bottom:1px solid var(--line);background:var(--st-present-bg);color:var(--st-present);font-weight:600}
.dlg{border:0;padding:0;border-radius:16px;width:min(500px,calc(100vw - 32px));max-height:calc(100dvh - 32px);background:var(--surface);color:var(--ink);box-shadow:0 24px 60px rgba(8,20,35,.35)}
.dlg::backdrop{background:rgba(15,42,68,.5)}
.dlg form{display:flex;flex-direction:column;max-height:calc(100dvh - 32px)}
.dlg-head{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:18px 20px;border-bottom:1px solid var(--line)}
.dlg-head h2{font-size:19px;font-weight:800}
.dlg-x{appearance:none;border:0;background:transparent;color:var(--muted);width:40px;height:40px;border-radius:10px;display:grid;place-items:center;cursor:pointer}
.dlg-x:hover{background:var(--bg);color:var(--ink)}
.dlg-body{padding:18px 20px;display:grid;gap:14px;overflow-y:auto}
.dlg-body .status:empty{display:none}
.dlg-body .status{color:var(--st-absent);font-weight:600}
.dlg-foot{display:flex;justify-content:flex-end;gap:10px;padding:14px 20px;border-top:1px solid var(--line)}
.bulk{display:grid;gap:14px}
.divider{border:0;border-top:1px solid var(--line);margin:4px 0;width:100%}

/* nhận xét */
.pill{font-size:13px;font-weight:600;border-radius:999px;padding:3px 10px;background:var(--bg);border:1px solid var(--line);font-variant-numeric:tabular-nums}

/* buổi học */
.bh-list{display:grid;gap:12px}
.ls{background:var(--surface);border:1.5px solid var(--line);border-radius:16px;overflow:hidden}
.ls-h{list-style:none;display:grid;grid-template-columns:72px minmax(150px,auto) minmax(0,1fr) auto 20px;gap:16px;align-items:center;padding:14px 20px;cursor:pointer}
.ls-h::-webkit-details-marker{display:none}
.ls-h:hover .ls-t{text-decoration:underline}
.ls-n{font-weight:800;color:var(--accent-ink);white-space:nowrap}
.ls-when b{display:block;font-weight:700;white-space:nowrap}
.ls-when small{color:var(--muted);font-size:13px;white-space:nowrap}
.ls-t{font-weight:600;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.ls-caret{color:var(--muted);transition:transform .15s}
.ls[open] .ls-caret{transform:rotate(180deg)}
.ls[open] .ls-h{border-bottom:1px solid var(--line)}
.ls-info{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:16px 24px;padding:16px 20px;border-bottom:1px solid var(--line);align-items:start}
.ls-info h4{margin:0 0 4px;font-size:12px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}
.ls-info p{margin:0;font-size:14.5px;line-height:1.55}
.ls-info .hwt{color:var(--focus)}
.ls-act{display:flex;gap:8px;flex-wrap:wrap;justify-content:flex-end;align-self:end}
table.ev{min-width:1000px}
table.ev td{vertical-align:top}
table.ev td:first-child{padding-top:14px}
table.ev td:nth-child(2){padding-top:16px}
table.ev select{width:100px}
table.ev input[type=text]{min-height:38px;padding:6px 10px;font-size:14px}
table.ev td:nth-child(4){width:170px}
table.ev td:nth-child(6){width:160px}
.ev-cm{min-width:280px;min-height:44px}
.fg3{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(0,1fr) minmax(0,1fr);gap:12px}
.fg3 > *{min-width:0}
.fg3 input{min-width:0;padding-left:10px;padding-right:8px}
.f-lab{font-weight:600;font-size:14px;margin-bottom:6px}
.dlg .seg{display:grid;grid-template-columns:repeat(2,minmax(0,1fr))}
.seg-b.on.pick{background:var(--ink);color:var(--surface)}
@media (max-width:680px){
  .ls-h{grid-template-columns:auto minmax(0,1fr) 20px;gap:6px 12px;padding:12px 16px}
  .ls-when{grid-column:2}
  .ls-t{grid-column:1/-1;white-space:normal}
  .ls-h .chip{grid-column:1/-1;justify-self:start}
  .ls-caret{grid-row:1;grid-column:3}
  .fg3{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
  .fg3 label:first-child{grid-column:1/-1}
}
@media (max-width:1040px){ .tq-grid{grid-template-columns:minmax(0,1fr)} }
@media (max-width:900px){
  .shell{grid-template-columns:minmax(0,1fr)}
  .app-side{position:static;height:auto;flex-direction:row;flex-wrap:wrap;align-items:center;padding:12px 12px 10px;gap:4px;padding-top:max(12px,env(safe-area-inset-top))}
  .side-brand{width:100%;padding:0 6px 8px}
  .side-b{flex:1 1 auto;justify-content:center;font-size:15px;padding:10px 8px}
  .side-foot{width:100%;margin-top:4px;padding:8px 6px 0;grid-template-columns:minmax(0,1fr) auto;align-items:center}
  .side-foot .side-home{grid-column:1/-1}
  .app-main{padding:20px 16px 48px}
}
@media (max-width:680px){
  .dd-row{grid-template-columns:24px 40px minmax(0,1fr);padding:12px 16px}
  .dd-row .seg{grid-column:1/-1;display:grid;grid-template-columns:repeat(4,minmax(0,1fr))}
  .seg-b{padding:8px 4px;font-size:14px}
  .box-h .sp{margin-left:0}
  .side-b svg{display:none}
}
@media (prefers-reduced-motion: reduce){ *{transition:none!important;scroll-behavior:auto!important} }