html,body{margin:0;min-height:100%}
html{-webkit-text-size-adjust:100%}
img{max-width:100%}
[hidden]{display:none!important}
:root{
  --bg:#F3F5FA;--surface:#FFFFFF;--surface2:#F8F9FD;--ink:#141B2D;--muted:#5A6379;--line:#DDE2EE;
  --accent:#2F4FD8;--accent-ink:#FFFFFF;--accent-soft:#E6EBFF;--hl:#FFE27A;--hl-ink:#141B2D;
  --ok:#178A55;--ok-soft:#E3F5EC;--bad:#C8382F;--bad-soft:#FCE9E7;--warn:#9A6A00;--warn-soft:#FFF4D6;
  --pen:#D2332B;--shadow:0 1px 2px rgba(20,27,45,.06),0 6px 20px rgba(20,27,45,.06);
  --f-display:"Lexend","Be Vietnam Pro",system-ui,sans-serif;
  --f-body:"Be Vietnam Pro",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --f-hand:"Patrick Hand","Comic Sans MS",cursive;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  color-scheme:dark;--bg:#0E1321;--surface:#161D2F;--surface2:#1B2338;--ink:#E7EBF6;--muted:#9AA3BA;--line:#2A3350;
  --accent:#8198FF;--accent-ink:#0E1321;--accent-soft:#1F2952;--hl:#E6C34A;--hl-ink:#141B2D;
  --ok:#43C98A;--ok-soft:#10301F;--bad:#FF7E72;--bad-soft:#3A1917;--warn:#F0C458;--warn-soft:#352A0E;--pen:#FF6B61;
  --shadow:0 1px 2px rgba(0,0,0,.3),0 8px 24px rgba(0,0,0,.25)}}
:root[data-theme="dark"]{
  color-scheme:dark;--bg:#0E1321;--surface:#161D2F;--surface2:#1B2338;--ink:#E7EBF6;--muted:#9AA3BA;--line:#2A3350;
  --accent:#8198FF;--accent-ink:#0E1321;--accent-soft:#1F2952;--hl:#E6C34A;--hl-ink:#141B2D;
  --ok:#43C98A;--ok-soft:#10301F;--bad:#FF7E72;--bad-soft:#3A1917;--warn:#F0C458;--warn-soft:#352A0E;--pen:#FF6B61;
  --shadow:0 1px 2px rgba(0,0,0,.3),0 8px 24px rgba(0,0,0,.25)}
*{box-sizing:border-box}
body{background:var(--bg);color:var(--ink);font-family:var(--f-body);font-size:16px;line-height:1.6}
button,input,textarea,select{font:inherit;color:inherit}
button{cursor:pointer}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:8px}
h1,h2,h3{font-family:var(--f-display);line-height:1.25;text-wrap:balance;margin:0}
.wrap{max-width:920px;margin:0 auto;padding-inline:16px}
.muted{color:var(--muted)}
.btn{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--line);background:var(--surface);padding:10px 16px;border-radius:12px;font-weight:600;transition:transform .08s,background .15s,border-color .15s}
.btn:hover{border-color:var(--accent)}
.btn:active{transform:translateY(1px)}
.btn.primary{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
.btn.primary:hover{filter:brightness(1.08)}
.btn.ghost{background:transparent;border-color:transparent}
.btn.ghost:hover{background:var(--accent-soft)}
.btn.sm{padding:6px 12px;font-size:14px;border-radius:10px}

/* ---------- login ---------- */
#login{min-height:100%;display:grid;place-items:center;padding-block:48px}
.login-card{width:100%;max-width:420px;background:var(--surface);border:1px solid var(--line);border-radius:20px;padding:32px 28px;box-shadow:var(--shadow)}
.brand{display:flex;align-items:center;gap:12px;margin-bottom:24px}
.brand-mark{width:48px;height:48px;border-radius:14px;background:var(--accent);color:var(--accent-ink);display:grid;place-items:center;font-family:var(--f-display);font-weight:700;font-size:20px;letter-spacing:-.5px}
.brand h1{font-size:22px}
.brand p{margin:0;font-size:14px;color:var(--muted)}
.field{display:grid;gap:6px;margin-bottom:16px}
.field label{font-size:14px;font-weight:600}
.field input{border:1.5px solid var(--line);background:var(--surface2);border-radius:12px;padding:12px 14px;font-size:16px}
.field input:focus{outline:none;border-color:var(--accent);background:var(--surface)}
.login-err{background:var(--bad-soft);color:var(--bad);border-radius:10px;padding:10px 12px;font-size:14px;margin-bottom:16px}
.login-card .btn.primary{width:100%;justify-content:center;padding:13px}
.login-foot{margin-top:18px;font-size:13px;color:var(--muted);text-align:center}

/* ---------- top bar ---------- */
.topbar{position:sticky;top:env(safe-area-inset-top,0px);z-index:20;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.topbar .wrap{display:flex;align-items:center;gap:12px;min-height:60px}
.topbar .brand{margin:0;gap:10px}
.topbar .brand-mark{width:36px;height:36px;border-radius:10px;font-size:15px}
.topbar .brand h1{font-size:16px}
.spacer{flex:1}
.user-chip{display:flex;align-items:center;gap:8px;font-size:14px;font-weight:600}
.avatar{width:30px;height:30px;border-radius:50%;background:var(--hl);color:var(--hl-ink);display:grid;place-items:center;font-weight:700;font-size:13px}

/* ---------- home ---------- */
.hero{padding-block:32px 8px}
.hero h2{font-size:clamp(24px,4vw,32px)}
.hero p{margin:8px 0 0;color:var(--muted);max-width:62ch}
.how{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.how span{font-size:13px;background:var(--surface);border:1px solid var(--line);border-radius:999px;padding:4px 12px;color:var(--muted)}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:16px;padding-block:24px 48px}
.ucard{position:relative;text-align:left;background:var(--surface);border:1px solid var(--line);border-radius:18px;padding:20px;display:grid;gap:4px;box-shadow:var(--shadow);transition:transform .12s,border-color .15s}
.ucard:hover{transform:translateY(-2px);border-color:var(--accent)}
.ucard .tag{font-family:var(--f-display);font-weight:600;font-size:13px;letter-spacing:.06em;text-transform:uppercase;color:var(--accent)}
.ucard.test .tag{color:var(--warn)}
.ucard h3{font-size:20px}
.ucard .vi{font-size:14px;color:var(--muted)}
.ucard .meta{display:flex;gap:12px;align-items:center;margin-top:12px;font-size:13px;color:var(--muted)}
.ucard .meta b{color:var(--ink);font-weight:600}
.grade{position:absolute;top:14px;right:14px;width:58px;height:58px;display:grid;place-items:center;font-family:var(--f-hand);font-size:28px;line-height:1;color:var(--pen)}
.grade svg{position:absolute;inset:0;width:100%;height:100%}
.grade.none{font-family:var(--f-body);font-size:12px;color:var(--muted);width:auto;height:auto;border:1px dashed var(--line);border-radius:999px;padding:3px 10px}

/* ---------- unit ---------- */
.uhead{padding-block:24px 8px;display:grid;gap:10px}
.uhead .tag{font-family:var(--f-display);font-weight:600;font-size:13px;letter-spacing:.06em;text-transform:uppercase;color:var(--accent)}
.uhead h2{font-size:clamp(24px,4vw,34px)}
.uhead .facts{display:flex;flex-wrap:wrap;gap:8px 16px;font-size:14px;color:var(--muted)}
.uhead .facts b{color:var(--ink)}
details.theory{background:var(--surface);border:1px solid var(--line);border-radius:16px;margin-top:8px}
details.theory summary{cursor:pointer;padding:14px 18px;font-weight:600;list-style:none;display:flex;align-items:center;gap:10px}
details.theory summary::-webkit-details-marker{display:none}
details.theory summary::before{content:"";width:8px;height:8px;border-right:2px solid var(--accent);border-bottom:2px solid var(--accent);transform:rotate(-45deg);transition:transform .15s}
details.theory[open] summary::before{transform:rotate(45deg)}
.theory-body{padding:0 18px 18px;font-size:15px}
.theory-body h3{font-size:17px;margin:18px 0 8px;color:var(--accent)}
.theory-body table{border-collapse:collapse;width:100%;font-size:14px}
.theory-body .tbl{overflow-x:auto;margin:8px 0}
.theory-body td,.theory-body th{border:1px solid var(--line);padding:6px 10px;vertical-align:top;text-align:left}
.theory-body th{background:var(--accent-soft)}
.theory-body p{margin:8px 0}
.secnav{display:flex;gap:8px;overflow-x:auto;padding-block:16px 4px;scrollbar-width:thin}
.secnav a{flex:none;font-size:13px;font-weight:600;text-decoration:none;color:var(--muted);background:var(--surface);border:1px solid var(--line);border-radius:999px;padding:5px 12px;white-space:nowrap}
.secnav a:hover{color:var(--accent);border-color:var(--accent)}
.secnav a .dot{display:inline-block;width:7px;height:7px;border-radius:50%;margin-right:6px;background:var(--line);vertical-align:1px}
.secnav a.full .dot{background:var(--accent)}
.secnav a.r-ok .dot{background:var(--ok)}.secnav a.r-mid .dot{background:var(--warn)}.secnav a.r-bad .dot{background:var(--bad)}

section.sec{margin-top:28px;scroll-margin-top:84px}
.sec-h{display:flex;align-items:baseline;gap:10px;flex-wrap:wrap;padding-bottom:10px;border-bottom:2px solid var(--line);margin-bottom:14px}
.sec-h h3{font-size:18px;flex:1;min-width:0}
.sec-h .pts{font-size:13px;color:var(--muted);white-space:nowrap}
.note{background:var(--warn-soft);color:var(--ink);border-radius:12px;padding:10px 14px;font-size:14px;margin-bottom:14px}
.note b{color:var(--warn)}
.passage{background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:18px 20px;margin-bottom:14px}
.passage h4{margin:0 0 8px;font-family:var(--f-display);font-size:16px}
.passage p{margin:0;font-size:16px;line-height:1.75}
.passage .trans{margin-top:12px;padding-top:12px;border-top:1px dashed var(--line);font-size:14px;color:var(--muted)}
.sub{font-weight:600;font-size:14px;color:var(--muted);margin:18px 0 8px;text-transform:uppercase;letter-spacing:.05em}
.matchbox{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:12px 16px;margin-bottom:14px;font-size:15px}
.matchbox b{display:block;font-size:13px;color:var(--muted);text-transform:uppercase;letter-spacing:.05em;margin-bottom:4px}
.matchbox div{padding:2px 0}

.audio{background:var(--accent-soft);border-radius:16px;padding:16px;margin-bottom:14px;display:grid;gap:10px}
.audio .row{display:flex;align-items:center;gap:12px;flex-wrap:wrap}
.audio .lbl{font-weight:600;font-family:var(--f-display)}
.audio audio{width:100%;max-width:100%}
.script{background:var(--surface);border-radius:12px;padding:12px 14px;font-size:14px}
.script p{margin:4px 0}.script b{color:var(--accent)}

.q{background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:16px 18px;margin-bottom:12px;transition:border-color .15s}
.q-top{display:flex;gap:12px;align-items:flex-start}
.qn{flex:none;min-width:32px;height:32px;padding:0 6px;border-radius:10px;background:var(--surface2);border:1px solid var(--line);display:grid;place-items:center;font-weight:700;font-size:14px;font-family:var(--f-display)}
.q.answered .qn{background:var(--accent-soft);border-color:transparent;color:var(--accent)}
.qtext{flex:1;min-width:0;padding-top:3px}
.qtext .src{display:block}
.qtext .tgt{display:block;margin-top:4px;color:var(--muted)}
.blank{display:inline-block;min-width:64px;border-bottom:2px solid var(--muted);margin:0 3px;height:1.1em;vertical-align:-2px}
.opts{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:8px;margin-top:12px;padding-left:44px}
.opts.long{grid-template-columns:1fr}
.opt{display:flex;gap:10px;align-items:flex-start;text-align:left;border:1.5px solid var(--line);background:var(--surface);border-radius:12px;padding:9px 12px;font-size:15px;line-height:1.45;transition:border-color .12s,background .12s}
.opt:hover:not(:disabled){border-color:var(--accent)}
.opt .L{flex:none;width:24px;height:24px;border-radius:7px;display:grid;place-items:center;font-size:13px;font-weight:700;background:var(--surface2);border:1px solid var(--line)}
.opt.sel{border-color:var(--accent);background:var(--accent-soft)}
.opt.sel .L{background:var(--accent);color:var(--accent-ink);border-color:var(--accent)}
.opt u{text-decoration:none;background:linear-gradient(transparent 55%,var(--hl) 55%);color:inherit;font-weight:700;padding:0 1px;border-bottom:2px solid var(--ink)}
.opt:disabled{cursor:default}
.opt.is-correct{border-color:var(--ok);background:var(--ok-soft)}
.opt.is-correct .L{background:var(--ok);border-color:var(--ok);color:#fff}
.opt.is-wrong{border-color:var(--bad);background:var(--bad-soft)}
.opt.is-wrong .L{background:var(--bad);border-color:var(--bad);color:#fff}
.fillin{display:inline-block;border:none;border-bottom:2px solid var(--accent);background:var(--accent-soft);border-radius:6px 6px 0 0;padding:1px 8px;margin:0 3px;min-width:90px;font-size:16px}
.fillin:focus{outline:none;background:var(--surface2);box-shadow:0 2px 0 var(--accent)}
.fillin.ok{border-color:var(--ok);background:var(--ok-soft)}
.fillin.bad{border-color:var(--bad);background:var(--bad-soft);text-decoration:line-through;text-decoration-color:var(--bad)}
.wr{margin-top:12px;padding-left:44px}
.wr textarea{width:100%;border:1.5px solid var(--line);background:var(--surface2);border-radius:12px;padding:10px 12px;font-size:16px;resize:vertical;min-height:48px;line-height:1.5}
.wr textarea:focus{outline:none;border-color:var(--accent);background:var(--surface)}
.wr textarea.ok{border-color:var(--ok);background:var(--ok-soft)}
.wr textarea.bad{border-color:var(--bad);background:var(--bad-soft)}
.ord{margin-top:12px;padding-left:44px;display:grid;gap:10px}
.ord .line{min-height:48px;border:1.5px dashed var(--line);border-radius:12px;padding:8px;display:flex;flex-wrap:wrap;gap:6px;align-items:center;background:var(--surface2)}
.ord .line:empty::before{content:"Bấm vào các cụm từ bên dưới để sắp xếp câu";color:var(--muted);font-size:14px;padding-left:4px}
.ord .line.ok{border-style:solid;border-color:var(--ok);background:var(--ok-soft)}
.ord .line.bad{border-style:solid;border-color:var(--bad);background:var(--bad-soft)}
.ord .pool{display:flex;flex-wrap:wrap;gap:6px}
.tile{border:1.5px solid var(--line);background:var(--surface);border-radius:10px;padding:5px 11px;font-size:15px;font-weight:500}
.tile:hover:not(:disabled){border-color:var(--accent)}
.line .tile{background:var(--accent-soft);border-color:transparent}
.tile:disabled{cursor:default}
.ord .tools{display:flex;gap:8px}
.fb{margin-top:12px;margin-left:44px;border-radius:12px;padding:10px 14px;font-size:14.5px;display:grid;gap:4px}
.fb.ok{background:var(--ok-soft)}
.fb.bad{background:var(--bad-soft)}
.fb .v{font-weight:700;display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.fb.ok .v{color:var(--ok)}.fb.bad .v{color:var(--bad)}
.fb .v small{font-weight:600;color:var(--muted)}
.fb .ans b{font-weight:700}
.fb .exp{color:var(--ink)}
.q.ok{border-color:color-mix(in srgb,var(--ok) 45%,var(--line))}
.q.bad{border-color:color-mix(in srgb,var(--bad) 45%,var(--line))}
.only-wrong .q.ok,.only-wrong .passage.hide-ok{display:none}

/* bottom bar */
.bbar{position:sticky;bottom:0;z-index:15;background:color-mix(in srgb,var(--surface) 94%,transparent);backdrop-filter:blur(10px);border-top:1px solid var(--line);padding-bottom:env(safe-area-inset-bottom,0px);margin-top:32px}
.bbar .wrap{display:flex;align-items:center;gap:14px;min-height:68px}
.prog{flex:1;display:grid;gap:5px;font-size:13px;color:var(--muted)}
.prog .track{height:8px;border-radius:99px;background:var(--line);overflow:hidden}
.prog .fill{height:100%;background:var(--accent);border-radius:99px;transition:width .2s}
.confirm{background:var(--warn-soft);border-radius:12px;padding:10px 14px;display:flex;flex-wrap:wrap;gap:10px;align-items:center;font-size:14px}

/* result */
.result{background:var(--surface);border:1px solid var(--line);border-radius:20px;padding:22px;margin-top:16px;box-shadow:var(--shadow);display:grid;grid-template-columns:auto 1fr;gap:22px;align-items:center}
.bigscore{position:relative;width:132px;height:132px;display:grid;place-items:center;color:var(--pen);font-family:var(--f-hand)}
.bigscore svg{position:absolute;inset:0;width:100%;height:100%}
.bigscore .n{font-size:54px;line-height:1}
.bigscore .d{font-size:18px;margin-top:-4px}
.bigscore .in{display:grid;justify-items:center}
.rs h3{font-size:22px}
.rs .msg{margin:4px 0 12px;color:var(--muted)}
.stats{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:14px}
.stat{border-radius:10px;padding:5px 12px;font-size:14px;font-weight:600}
.stat.ok{background:var(--ok-soft);color:var(--ok)}.stat.bad{background:var(--bad-soft);color:var(--bad)}.stat.skip{background:var(--surface2);color:var(--muted);border:1px solid var(--line)}
.rs .actions{display:flex;flex-wrap:wrap;gap:8px}
.breakdown{grid-column:1/-1;display:grid;gap:6px;border-top:1px solid var(--line);padding-top:14px}
.brow{display:grid;grid-template-columns:minmax(0,1fr) 120px 56px;gap:12px;align-items:center;font-size:14px}
.brow .t{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.brow .bar{height:7px;border-radius:99px;background:var(--line);overflow:hidden}
.brow .bar i{display:block;height:100%;background:var(--ok)}
.brow .c{text-align:right;font-variant-numeric:tabular-nums;color:var(--muted)}
@media (max-width:560px){
  .result{grid-template-columns:1fr;justify-items:start}
  .opts,.wr,.ord{padding-left:0}.fb{margin-left:0}
  .brow{grid-template-columns:minmax(0,1fr) 70px 48px}
  .user-chip .nm{display:none}
  .q{padding:14px}
}
@media (prefers-reduced-motion:reduce){*{transition:none!important}}
.btn{white-space:nowrap}
@media (max-width:420px){.topbar .brand h1{font-size:15px;line-height:1.2}}

/* ---------- admin ---------- */
.brand-btn{background:none;border:0;padding:0;color:inherit;text-align:left}
.role{display:inline-block;font-size:11px;font-weight:700;letter-spacing:.04em;text-transform:uppercase;background:var(--hl);color:var(--hl-ink);border-radius:6px;padding:1px 6px;margin-left:4px;vertical-align:1px}
.sync{display:inline-block;margin-top:12px;font-size:13.5px;font-weight:600;border-radius:8px;padding:4px 10px}
.sync.ok{background:var(--ok-soft);color:var(--ok)}.sync.bad{background:var(--bad-soft);color:var(--bad)}.sync.wait{background:var(--surface2);color:var(--muted)}
.tabs{display:flex;gap:4px;border-bottom:2px solid var(--line);margin:16px 0 20px}
.tab{background:none;border:0;border-bottom:3px solid transparent;margin-bottom:-2px;padding:10px 14px;font-weight:600;color:var(--muted)}
.tab.on{color:var(--accent);border-bottom-color:var(--accent)}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:18px 20px;display:grid;gap:12px;align-content:start}
.panel h3{font-size:17px}
.panel p{margin:0}
.twocol{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:16px;margin-bottom:8px}
.fgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:4px 12px}
.fgrid .field{margin-bottom:8px}
.field select,.filters select,.filters input{border:1.5px solid var(--line);background:var(--surface2);border-radius:10px;padding:9px 10px;font-size:15px}
.field input[readonly]{opacity:.7}
.check{display:flex;align-items:center;gap:8px;font-size:14px;font-weight:600;align-self:end;padding-bottom:12px}
.check input{width:18px;height:18px;accent-color:var(--accent)}
.row-btns{display:flex;gap:8px;flex-wrap:wrap}
.panel textarea{width:100%;border:1.5px solid var(--line);background:var(--surface2);border-radius:12px;padding:10px 12px;font-size:14px;font-family:ui-monospace,Consolas,monospace;resize:vertical}
.msg{border-radius:10px;padding:9px 12px;font-size:14px}
.msg.ok{background:var(--ok-soft);color:var(--ok)}.msg.bad{background:var(--bad-soft);color:var(--bad)}
.filters{display:flex;flex-wrap:wrap;gap:12px;align-items:end;margin-bottom:16px}
.filters label{display:grid;gap:4px;font-size:13px;font-weight:600;color:var(--muted)}
.filters .grow{flex:1;min-width:180px}
.filters .grow input{width:100%}
.kpis{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px;margin-bottom:24px}
.kpi{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:14px 16px;display:grid}
.kpi b{font-family:var(--f-display);font-size:26px;font-variant-numeric:tabular-nums}
.kpi span{font-size:13px;color:var(--muted)}
.h3{font-size:17px;margin:24px 0 10px}
.sm{font-size:13px}
.tblwrap{overflow-x:auto;background:var(--surface);border:1px solid var(--line);border-radius:14px}
.dt{border-collapse:collapse;width:100%;font-size:14px}
.dt th{text-align:left;font-size:12.5px;text-transform:uppercase;letter-spacing:.04em;color:var(--muted);background:var(--surface2);padding:10px 12px;border-bottom:1px solid var(--line);white-space:nowrap}
.dt td{padding:9px 12px;border-bottom:1px solid var(--line);vertical-align:middle}
.dt tr:last-child td{border-bottom:0}
.dt .c{text-align:center}.dt .nw{white-space:nowrap}
.dt code{font-size:13px;background:var(--surface2);border-radius:6px;padding:1px 6px}
.sc{display:inline-block;min-width:44px;border-radius:8px;padding:2px 8px;font-weight:700;font-variant-numeric:tabular-nums;color:var(--muted)}
.sc.hi{background:var(--ok-soft);color:var(--ok)}.sc.mid{background:var(--warn-soft);color:var(--warn)}.sc.lo{background:var(--bad-soft);color:var(--bad)}
.pill{display:inline-block;font-size:12px;font-weight:700;border-radius:999px;padding:2px 10px;background:var(--surface2);border:1px solid var(--line);color:var(--muted);white-space:nowrap}
.pill.admin{background:var(--hl);color:var(--hl-ink);border-color:transparent}
.pill.ok{background:var(--ok-soft);color:var(--ok);border-color:transparent}
.pill.off{background:var(--bad-soft);color:var(--bad);border-color:transparent}
.btn.danger{background:var(--bad);border-color:var(--bad);color:#fff}
.admin-main{padding-bottom:48px}
.field input,.field select{width:100%;min-width:0}
@media (max-width:560px){.topbar .brand h1{display:none}}

/* ---------- thanh cài app ---------- */
.install-bar{position:fixed;left:12px;right:12px;bottom:calc(12px + env(safe-area-inset-bottom));z-index:50;
  display:flex;align-items:center;gap:12px;max-width:560px;margin:0 auto;padding:12px 12px 12px 14px;
  background:var(--surface);color:var(--ink);border:1px solid var(--line);border-radius:16px;
  box-shadow:0 10px 30px rgba(20,27,45,.18)}
.install-bar img{flex:none;border-radius:10px}
.install-txt{flex:1;min-width:0;display:flex;flex-direction:column;gap:2px;font-size:14px;line-height:1.4}
.install-txt span{color:var(--muted)}
.install-txt b{color:var(--ink)}
.install-x{flex:none;align-self:flex-start;width:32px;height:32px;border:0;background:none;color:var(--muted);font-size:22px;line-height:1;cursor:pointer;border-radius:8px}
.install-x:hover{background:var(--surface2)}

/* =====================================================================
   TRANG TRÍ NỀN — banner xanh dương, tia sáng, ngôi sao, chữ vàng
   ===================================================================== */
:root{
  --b1:#0A2FB8;--b2:#1E5BF0;--b3:#0B2A9A;--gold:#FFD23F;--gold2:#FFB800;
  --sparkle:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220'%3E%3Cg fill='%23fff'%3E%3Cpath d='M30 20l2.5 7 7 2.5-7 2.5-2.5 7-2.5-7-7-2.5 7-2.5z' opacity='.7'/%3E%3Cpath d='M160 60l1.6 4.4 4.4 1.6-4.4 1.6-1.6 4.4-1.6-4.4-4.4-1.6 4.4-1.6z' opacity='.55'/%3E%3Cpath d='M95 150l2 5.5 5.5 2-5.5 2-2 5.5-2-5.5-5.5-2 5.5-2z' opacity='.5'/%3E%3Ccircle cx='190' cy='170' r='1.8' opacity='.7'/%3E%3Ccircle cx='60' cy='110' r='1.3' opacity='.6'/%3E%3Ccircle cx='130' cy='20' r='1.2' opacity='.5'/%3E%3Ccircle cx='20' cy='190' r='1.6' opacity='.45'/%3E%3C/g%3E%3Cg fill='%23FFD23F'%3E%3Cpath d='M205 110l4 4-4 4-4-4z' opacity='.8'/%3E%3Cpath d='M70 60l3 3-3 3-3-3z' opacity='.7'/%3E%3C/g%3E%3C/svg%3E");
  --banner:
    radial-gradient(circle at 82% 18%,rgba(140,190,255,.55),transparent 38%),
    radial-gradient(circle at 10% 110%,rgba(0,18,90,.55),transparent 50%),
    linear-gradient(115deg,transparent 0 58%,rgba(255,255,255,.08) 58% 66%,transparent 66% 70%,rgba(255,255,255,.06) 70% 73%,transparent 73%),
    linear-gradient(135deg,var(--b1) 0%,var(--b2) 52%,var(--b3) 100%);
}
body{background:
  radial-gradient(900px 420px at 85% -80px,rgba(47,91,240,.16),transparent 70%),
  radial-gradient(700px 380px at -10% -60px,rgba(255,210,63,.14),transparent 70%),
  linear-gradient(180deg,#E6EEFF 0,var(--bg) 520px) no-repeat,var(--bg)}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) body{background:
  radial-gradient(900px 420px at 85% -80px,rgba(47,91,240,.28),transparent 70%),linear-gradient(180deg,#111C3F 0,var(--bg) 520px) no-repeat,var(--bg)}}
:root[data-theme="dark"] body{background:radial-gradient(900px 420px at 85% -80px,rgba(47,91,240,.28),transparent 70%),linear-gradient(180deg,#111C3F 0,var(--bg) 520px) no-repeat,var(--bg)}

/* ---------- banner dùng chung ---------- */
.banner{position:relative;isolation:isolate;overflow:hidden;background:var(--banner);color:#fff;border-radius:24px;
  padding:28px 28px 26px;margin-top:20px;box-shadow:0 18px 40px -18px rgba(10,47,184,.6)}
.banner::before{content:"";position:absolute;inset:0;z-index:-1;background:var(--sparkle);opacity:.9;pointer-events:none}
.banner::after{content:"";position:absolute;z-index:-1;width:340px;height:340px;right:-120px;bottom:-190px;border-radius:50%;
  border:2px solid rgba(255,255,255,.12);box-shadow:0 0 0 36px rgba(255,255,255,.04),0 0 0 72px rgba(255,255,255,.03);pointer-events:none}
.banner h2{color:#fff}
.banner p{color:rgba(255,255,255,.86)}
.banner b{color:#fff}
.banner .gold,.banner .tag{background:linear-gradient(180deg,#FFF1A8 0%,var(--gold) 45%,var(--gold2) 100%);-webkit-background-clip:text;background-clip:text;color:transparent}
.banner .tag{font-size:14px;letter-spacing:.1em;justify-self:start}
.banner .facts{color:rgba(255,255,255,.82)}
.banner .facts b{color:var(--gold)}
.banner .btn.ghost{color:#fff}
.banner .btn.ghost:hover{background:rgba(255,255,255,.14)}
.banner .btn:not(.ghost):not(.primary){background:rgba(255,255,255,.14);border-color:rgba(255,255,255,.35);color:#fff}
.banner .btn:not(.ghost):not(.primary):hover{background:rgba(255,255,255,.22);border-color:#fff}
.banner .theory{color:var(--ink)}
.banner .theory b{color:inherit}
.banner .theory p{color:inherit}

/* ---------- banner trang chủ ---------- */
.hero.banner{display:grid;grid-template-columns:1fr 230px;gap:12px;align-items:center;padding:30px 30px 26px}
.hero.banner h2{font-size:clamp(26px,4.4vw,38px);font-weight:700;letter-spacing:-.01em;line-height:1.18;margin-top:12px;text-shadow:0 2px 12px rgba(0,20,90,.35)}
.hero.banner p{max-width:54ch;font-size:15px}
.pill-y{display:inline-flex;align-items:center;gap:6px;font-family:var(--f-display);font-weight:600;font-size:12.5px;letter-spacing:.06em;text-transform:uppercase;
  background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.28);border-radius:999px;padding:5px 14px}
.pill-y::before{content:"";width:7px;height:7px;border-radius:50%;background:var(--gold);box-shadow:0 0 0 3px rgba(255,210,63,.3)}
.feats{display:flex;flex-wrap:wrap;gap:10px 22px;margin-top:18px}
.feat{display:flex;align-items:center;gap:10px;font-size:13.5px;line-height:1.3;color:rgba(255,255,255,.85)}
.feat svg{flex:none;width:38px;height:38px;padding:7px;border-radius:12px;background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.25);color:var(--gold)}
.feat b{display:block;font-size:15px;color:#fff}
.hero.banner .how{margin-top:18px}
.hero.banner .how span{background:rgba(6,26,107,.35);border-color:rgba(255,255,255,.18);color:rgba(255,255,255,.88)}
.hero-art svg{width:100%;height:auto;display:block;filter:drop-shadow(0 12px 18px rgba(0,16,80,.35));animation:float 6s ease-in-out infinite}
@keyframes float{50%{transform:translateY(-6px)}}
@media (prefers-reduced-motion:reduce){.hero-art svg{animation:none}}
@media (max-width:680px){
  .hero.banner{grid-template-columns:1fr;padding:22px 18px 20px}
  .hero-art{position:absolute;right:-18px;top:6px;width:120px;opacity:.35;z-index:-1}
  .feats{gap:10px 16px}
  .banner{border-radius:20px}
}
.ucard{border-top:4px solid var(--accent)}
.ucard.test{border-top-color:var(--gold2)}

/* ---------- banner trang Unit / Quản trị ---------- */
.uhead.banner{padding:22px 24px}
.uhead.banner h2 .muted{color:rgba(255,255,255,.72)!important}
@media (max-width:680px){.uhead.banner{padding:18px 16px}}

/* ---------- trang đăng nhập ---------- */
#login{position:relative;isolation:isolate;max-width:none;min-height:100vh;min-height:100dvh;background:var(--banner);align-content:center;gap:22px}
#login::before{content:"";position:fixed;inset:0;z-index:-1;background:var(--sparkle);pointer-events:none}
.login-deco{text-align:center;color:#fff}
.login-deco .script-tag{margin:0;font-family:var(--f-hand);font-size:clamp(22px,4vw,30px);color:rgba(255,255,255,.92);transform:rotate(-2deg)}
.login-deco .big-tag{margin:2px 0 0;font-family:var(--f-display);font-weight:700;font-size:clamp(24px,5vw,38px);text-transform:uppercase;letter-spacing:.01em;text-shadow:0 3px 14px rgba(0,20,90,.4)}
.login-deco .big-tag b{background:linear-gradient(180deg,#FFF1A8,var(--gold) 45%,var(--gold2));-webkit-background-clip:text;background-clip:text;color:transparent}
.login-card{box-shadow:0 24px 60px -20px rgba(0,16,80,.6);border-color:transparent}

/* ---------- xem câu sai (admin) ---------- */
body.modal-open{overflow:hidden}
.modal{position:fixed;inset:0;z-index:60;background:rgba(8,14,40,.55);backdrop-filter:blur(3px);display:grid;place-items:center;padding:16px}
.modal-card{width:100%;max-width:760px;max-height:calc(100dvh - 32px);display:flex;flex-direction:column;background:var(--bg);border-radius:20px;overflow:hidden;box-shadow:0 30px 80px rgba(0,0,0,.35)}
.modal-h{display:flex;gap:12px;align-items:flex-start;padding:18px 20px;background:var(--banner);color:#fff}
.modal-h>div{flex:1;min-width:0}
.modal-h h3{font-size:18px;color:#fff}
.modal-h .muted{color:rgba(255,255,255,.8)}
.modal-h b{color:var(--gold)}
.modal-h .t-bad{color:#FFC2BC;font-weight:600}
.modal-h .install-x{color:#fff}
.modal-h .install-x:hover{background:rgba(255,255,255,.15)}
.modal-b{overflow-y:auto;padding:16px 20px 22px;overscroll-behavior:contain}
.dsec{margin:14px 0 8px;font-family:var(--f-display);font-size:14px;color:var(--accent)}
.dsec:first-child{margin-top:0}
.dq{background:var(--surface);border:1px solid var(--line);border-left:4px solid var(--bad);border-radius:14px;padding:12px 14px;margin-bottom:10px;display:grid;gap:8px}
.dq-h{display:flex;gap:10px;align-items:flex-start}
.dq-h .qn{flex:none;min-width:28px;height:28px;padding:0 6px;border-radius:8px;background:var(--bad-soft);color:var(--bad);display:grid;place-items:center;font-weight:700;font-size:13px}
.dq-t{flex:1;min-width:0;padding-top:2px}
.dq-p{font-size:14px;background:var(--surface2);border-radius:10px;padding:6px 10px}
.dq-p summary{cursor:pointer;font-weight:600;color:var(--accent)}
.dq-p p{margin:6px 0 2px;line-height:1.7}
.dq-opts{display:flex;flex-wrap:wrap;gap:6px}
.dq-opt{font-size:14px;border:1px solid var(--line);border-radius:8px;padding:3px 10px;background:var(--surface2)}
.dq-opt.cor{border-color:var(--ok);background:var(--ok-soft);color:var(--ok);font-weight:600}
.dq-opt.pick:not(.cor){border-color:var(--bad);background:var(--bad-soft);color:var(--bad);font-weight:600}
.dq-row{display:flex;gap:10px;align-items:baseline;font-size:14.5px;border-radius:8px;padding:5px 10px}
.dq-row .lb{flex:none;width:72px;font-size:12px;font-weight:700;text-transform:uppercase;letter-spacing:.04em}
.dq-row.bad{background:var(--bad-soft)}.dq-row.bad .lb,.dq-row.bad b{color:var(--bad)}
.dq-row.skip{background:var(--surface2)}.dq-row.skip .lb,.dq-row.skip b{color:var(--muted)}
.dq-row.ok{background:var(--ok-soft)}.dq-row.ok .lb,.dq-row.ok b{color:var(--ok)}
.dq-exp{font-size:14px;color:var(--muted);border-top:1px dashed var(--line);padding-top:8px}