/* Layout: exam booklet for students (index + question card); editor workbench for teachers (outline + inspector) */
:root{
  --bg:#ECF1F1; --surface:#FFFFFF; --ink:#14222A; --muted:#58696F; --line:#D1DCDE;
  --chip:#DFE8EA; --accent:#0B5F75; --accent-ink:#FFFFFF; --accent-soft:#D9ECF1;
  --ok:#2C7A4D; --ok-bg:#E2F1E7; --bad:#B03A2A; --bad-bg:#F7E2DD; --warn:#8F6511; --warn-bg:#F6ECD6;
  --display:"Young Serif", Georgia, "Times New Roman", serif;
  --body:"Atkinson Hyperlegible", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono:"IBM Plex Mono", ui-monospace, Consolas, monospace;
  --scene-filter:none;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#0E1619; --surface:#152025; --ink:#E2ECEE; --muted:#94A9AF; --line:#29393F;
    --chip:#1F2E33; --accent:#5DBAD4; --accent-ink:#04212B; --accent-soft:#143542;
    --ok:#62C48D; --ok-bg:#15301F; --bad:#F2846F; --bad-bg:#3A1C17; --warn:#E2B65A; --warn-bg:#352A12;
    --scene-filter:brightness(.92) saturate(.95);
    color-scheme:dark;
  }
}
:root[data-theme="dark"]{
  --bg:#0E1619; --surface:#152025; --ink:#E2ECEE; --muted:#94A9AF; --line:#29393F;
  --chip:#1F2E33; --accent:#5DBAD4; --accent-ink:#04212B; --accent-soft:#143542;
  --ok:#62C48D; --ok-bg:#15301F; --bad:#F2846F; --bad-bg:#3A1C17; --warn:#E2B65A; --warn-bg:#352A12;
  --scene-filter:brightness(.92) saturate(.95);
  color-scheme:dark;
}
*{box-sizing:border-box}
[hidden]{display:none!important}
body{margin:0}
body{background:var(--bg);color:var(--ink);font-family:var(--body);font-size:16px;line-height:1.5}
button,input,select,textarea{font:inherit;color:inherit}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px}
.wrap{max-width:1180px;margin:0 auto;padding-block:28px 48px;
  padding-left:max(16px, env(safe-area-inset-left, 0px));padding-right:max(16px, env(safe-area-inset-right, 0px))}
.eyebrow{font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}

/* ---------- Student runner ---------- */
header.top{display:flex;flex-wrap:wrap;align-items:end;justify-content:space-between;gap:12px 24px;margin-bottom:24px}
.brand h1{font-family:var(--display);font-weight:400;font-size:clamp(28px,4vw,38px);line-height:1.1;margin:0;text-wrap:balance}
.brand p{margin:4px 0 0;color:var(--muted)}
.progress{min-width:min(280px,100%);flex:0 1 320px}
.progress .bar{height:6px;border-radius:3px;background:var(--chip);overflow:hidden;margin-top:6px}
.progress .bar i{display:block;height:100%;background:var(--accent);transition:width .3s ease}
.progress .row{display:flex;justify-content:space-between;gap:12px;font-variant-numeric:tabular-nums}
.app{display:grid;grid-template-columns:270px minmax(0,1fr);gap:24px;align-items:start}
nav.index{background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:8px;position:sticky;top:calc(env(safe-area-inset-top, 0px) + 16px);max-height:calc(100vh - 32px);overflow-y:auto}
nav.index ol{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:1px}
nav.index li.sec{padding:12px 10px 4px;font-family:var(--mono);font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.qbtn{width:100%;display:grid;grid-template-columns:26px minmax(0,1fr) auto;align-items:center;gap:8px;background:none;border:0;border-radius:7px;padding:5px 10px;text-align:left;cursor:pointer}
.qbtn:hover{background:var(--chip)}
.qbtn[aria-current="true"]{background:var(--accent-soft)}
.qbtn .n{font-family:var(--mono);font-size:13px;color:var(--muted);font-variant-numeric:tabular-nums}
.qbtn .t{display:flex;flex-direction:column;min-width:0}
.qbtn .t b{font-weight:700;font-size:14px}
.qbtn .t span{font-size:12px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.qbtn .t span.img{color:var(--accent);font-weight:700}
.dot{width:10px;height:10px;border-radius:50%;border:2px solid var(--line)}
.dot.done{background:var(--accent);border-color:var(--accent)}
.dot.ok{background:var(--ok);border-color:var(--ok)}
.dot.bad{background:var(--bad);border-color:var(--bad)}
li.end{margin-top:6px;border-top:1px solid var(--line);padding-top:6px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:clamp(18px,3vw,32px);display:flex;flex-direction:column;gap:20px;min-width:0}
.qhead{display:flex;flex-wrap:wrap;align-items:center;gap:8px 12px}
.chip{font-family:var(--mono);font-size:12px;letter-spacing:.04em;background:var(--chip);color:var(--ink);padding:3px 9px;border-radius:999px}
.chip.img{background:var(--accent);color:var(--accent-ink)}
.card h2{font-family:var(--display);font-weight:400;font-size:clamp(24px,3vw,30px);line-height:1.15;margin:0;text-wrap:balance}
.qtext{margin:0;max-width:62ch;font-size:clamp(18px,2vw,20px);font-weight:700;line-height:1.4;text-wrap:pretty;white-space:pre-line}
.prose{max-width:65ch;margin:0}
.prose p{margin:0 0 10px}
.opts{display:flex;flex-direction:column;gap:8px;max-width:720px}
.opt{display:flex;align-items:center;gap:12px;border:1.5px solid var(--line);border-radius:9px;padding:12px 14px;cursor:pointer;background:var(--surface);transition:border-color .15s,background .15s}
.opt:hover{border-color:var(--accent)}
.opt input{position:absolute;opacity:0;pointer-events:none}
.opt .key{flex:none;width:28px;height:28px;display:grid;place-items:center;border-radius:6px;background:var(--chip);font-family:var(--mono);font-size:13px}
.opt.is-sel{border-color:var(--accent);background:var(--accent-soft)}
.opt.is-sel .key{background:var(--accent);color:var(--accent-ink)}
.opt:has(input:focus-visible){outline:3px solid var(--accent);outline-offset:2px}
.opt.is-right{border-color:var(--ok);background:var(--ok-bg)}
.opt.is-right .key{background:var(--ok);color:var(--surface)}
.opt.is-wrong{border-color:var(--bad);background:var(--bad-bg)}
.opt.is-wrong .key{background:var(--bad);color:var(--surface)}
.opt.locked{cursor:default}
.opt.locked:hover{border-color:inherit}
.target{display:flex;flex-wrap:wrap;align-items:end;justify-content:space-between;gap:10px 20px;border:1.5px dashed var(--accent);border-radius:10px;padding:14px 18px;background:var(--accent-soft)}
.target .who{display:flex;flex-direction:column;gap:2px}
.target .name{font-family:var(--display);font-size:clamp(24px,4vw,34px);line-height:1.05}
.target .sci{font-style:italic;color:var(--muted)}
.scene{border-radius:10px;overflow:hidden;border:1px solid var(--line);line-height:0;background:var(--chip)}
.scene svg{width:100%;height:auto;display:block;touch-action:manipulation}
.scene svg image{filter:var(--scene-filter)}
.zone{cursor:crosshair;outline:none}
.zone ellipse{fill:transparent;stroke:transparent;stroke-width:2;stroke-dasharray:5 4;transition:fill .15s}
.zone:hover ellipse,.zone:focus-visible ellipse{fill:rgba(255,255,255,.35);stroke:#ffffff}
.scene.done .zone{cursor:default}
.scene.done .zone:hover ellipse{fill:transparent;stroke:transparent}
.zone.sel ellipse{fill:rgba(11,95,117,.30)!important;stroke:#0b5f75!important;stroke-dasharray:none;stroke-width:3}
.zone.right ellipse{fill:rgba(60,190,110,.30)!important;stroke:#1f8a4b!important;stroke-dasharray:none;stroke-width:3}
.zone.wrong ellipse{fill:rgba(230,80,60,.28)!important;stroke:#c23a28!important;stroke-dasharray:none;stroke-width:3}
.legend{display:flex;flex-wrap:wrap;gap:6px 14px;font-size:13px;color:var(--muted);margin:0}
.feedback{border-radius:9px;padding:12px 16px;display:flex;flex-direction:column;gap:4px;max-width:760px}
.feedback b{font-size:16px}
.feedback.ok{background:var(--ok-bg);border-left:4px solid var(--ok)}
.feedback.bad{background:var(--bad-bg);border-left:4px solid var(--bad)}
.feedback.warn{background:var(--warn-bg);border-left:4px solid var(--warn)}
.feedback ul{margin:4px 0 0;padding-left:20px}
.actions{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:10px;border-top:1px solid var(--line);padding-top:18px}
.actions .right{display:flex;flex-wrap:wrap;gap:10px;margin-left:auto;align-items:center}
.btn{border:1.5px solid var(--line);background:var(--surface);border-radius:8px;padding:10px 18px;font-weight:700;cursor:pointer}
.btn:hover{border-color:var(--ink)}
.btn.primary{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
.btn.primary:hover{filter:brightness(1.08)}
.btn.danger{background:var(--bad);border-color:var(--bad);color:var(--surface)}
.btn.sm{padding:6px 12px;font-size:14px}
.btn:disabled{opacity:.45;cursor:not-allowed;filter:none}
.saved{font-size:14px;color:var(--muted)}
.facts{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:10px;margin:0;padding:0;list-style:none}
.facts li{border:1px solid var(--line);border-radius:9px;padding:12px 14px;display:flex;flex-direction:column;gap:2px}
.facts b{font-family:var(--display);font-weight:400;font-size:26px;font-variant-numeric:tabular-nums}
table.sections{border-collapse:collapse;width:100%;max-width:560px;font-variant-numeric:tabular-nums}
table.sections th,table.sections td{text-align:left;padding:8px 10px;border-bottom:1px solid var(--line)}
table.sections th{font-family:var(--mono);font-size:12px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);font-weight:500}
table.sections .num{text-align:right}
.score{display:flex;flex-wrap:wrap;align-items:baseline;gap:8px 16px}
.score .big{font-family:var(--display);font-size:clamp(44px,8vw,64px);line-height:1;font-variant-numeric:tabular-nums}
.pill{font-family:var(--mono);font-size:12px;padding:3px 9px;border-radius:999px;white-space:nowrap}
.pill.ok{background:var(--ok-bg);color:var(--ok)}
.pill.bad{background:var(--bad-bg);color:var(--bad)}
.pill.pending{background:var(--chip);color:var(--muted)}
.rlist{list-style:none;margin:0;padding:0;border-top:1px solid var(--line)}
.rlist li button{width:100%;display:grid;grid-template-columns:34px minmax(0,1fr) auto auto;gap:12px;align-items:center;padding:9px 4px;border:0;border-bottom:1px solid var(--line);background:none;text-align:left;cursor:pointer}
.rlist li button:hover{background:var(--chip)}
.rlist .n{font-family:var(--mono);color:var(--muted);font-variant-numeric:tabular-nums}
.rlist .d{min-width:0;font-size:14px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.rlist .d em{font-style:normal;font-family:var(--mono);font-size:11px;color:var(--accent);margin-right:6px}
.rlist .p{font-family:var(--mono);font-size:13px;color:var(--muted);font-variant-numeric:tabular-nums}
.certbox{display:flex;flex-direction:column;gap:14px;border:1px solid var(--line);border-radius:10px;padding:18px;background:var(--bg)}
.field{display:flex;flex-direction:column;gap:6px;min-width:0}
.field>label,.field>.lbl{font-weight:700;font-size:14px}
.field .help{font-size:13px;color:var(--muted)}
.in{background:var(--surface);border:1.5px solid var(--line);border-radius:8px;padding:9px 12px;width:100%;min-width:0}
.in:focus{border-color:var(--accent);outline:none}
textarea.in{resize:vertical;min-height:80px;line-height:1.5}
.certrow{display:flex;flex-wrap:wrap;gap:10px;align-items:center}
.msg{font-size:14px;margin:0}
.msg.bad{color:var(--bad)}
.msg.ok{color:var(--ok)}
.teacherbar{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px 14px;background:var(--warn-bg);border:1px solid var(--line);border-radius:10px;padding:10px 14px;margin-bottom:18px;font-size:14px}

/* ---------- Editor ---------- */
.ed-top{position:sticky;top:env(safe-area-inset-top, 0px);z-index:5;background:var(--surface);border-bottom:1px solid var(--line)}
.ed-top .wrap{padding-block:12px;display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px 16px}
.ed-top h1{font-family:var(--display);font-weight:400;font-size:22px;margin:0;line-height:1.2}
.ed-top .st{font-size:13px;color:var(--muted)}
.ed-top .acts{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.ed{display:grid;grid-template-columns:300px minmax(0,1fr);gap:20px;align-items:start}
.ed-side{background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:8px;position:sticky;top:calc(env(safe-area-inset-top, 0px) + 84px);max-height:calc(100vh - 100px);overflow-y:auto}
.ed-side ol{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:1px}
.ed-side .grp{display:flex;align-items:center;justify-content:space-between;gap:8px;padding:12px 10px 4px}
.ed-side .add{background:none;border:0;color:var(--accent);font-weight:700;font-size:13px;cursor:pointer;padding:2px 4px}
.sbtn{width:100%;display:grid;grid-template-columns:24px minmax(0,1fr);gap:8px;align-items:start;background:none;border:0;border-radius:7px;padding:6px 10px;text-align:left;cursor:pointer;font-size:14px}
.sbtn:hover{background:var(--chip)}
.sbtn[aria-current="true"]{background:var(--accent-soft)}
.sbtn .n{font-family:var(--mono);font-size:12px;color:var(--muted);padding-top:2px}
.sbtn .t{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.sbtn .ty{display:block;font-size:12px;color:var(--muted)}
.sbtn .ty.img{color:var(--accent);font-weight:700}
.sbtn .warn{color:var(--bad);font-weight:700}
.panel{display:flex;flex-direction:column;gap:18px}
.grid2{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px}
.optrow{display:grid;grid-template-columns:auto 28px minmax(0,1fr) auto;gap:8px;align-items:center}
.optrow input[type=radio]{width:18px;height:18px;accent-color:var(--ok)}
.iconbtns{display:flex;flex-wrap:wrap;gap:4px}
.ib{border:1px solid var(--line);background:var(--surface);border-radius:6px;width:32px;height:32px;display:grid;place-items:center;cursor:pointer;font-size:14px}
.ib:hover{border-color:var(--ink)}
.ib:disabled{opacity:.35;cursor:not-allowed}
.zwrap{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:14px;align-items:start}
.zcanvas{border-radius:10px;overflow:hidden;border:1px solid var(--line);line-height:0;background:var(--chip);touch-action:none}
.zcanvas svg{width:100%;height:auto;display:block;user-select:none}
.zcanvas.draw svg{cursor:crosshair}
.zed ellipse{fill:rgba(11,95,117,.16);stroke:#0b5f75;stroke-width:2;cursor:move}
.zed.ok ellipse{fill:rgba(44,160,90,.22);stroke:#1f8a4b}
.zed.on ellipse{stroke-width:4;stroke-dasharray:7 4}
.zed text{font-family:var(--mono);font-weight:500;fill:#fff;paint-order:stroke;stroke:#0b2a33;stroke-width:3px;pointer-events:none}
.zlist{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:4px;max-height:260px;overflow:auto}
.zlist button{width:100%;display:grid;grid-template-columns:26px minmax(0,1fr) auto;gap:6px;align-items:center;border:1px solid var(--line);border-radius:7px;background:var(--surface);padding:6px 8px;text-align:left;cursor:pointer;font-size:14px}
.zlist button[aria-current="true"]{border-color:var(--accent);background:var(--accent-soft)}
.zlist .n{font-family:var(--mono);font-size:12px;color:var(--muted)}
.zlist .t{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.zpanel{border:1px solid var(--line);border-radius:10px;padding:12px;display:flex;flex-direction:column;gap:10px;background:var(--bg)}
.range{display:grid;grid-template-columns:70px minmax(0,1fr) 44px;gap:8px;align-items:center;font-size:13px}
.range input{width:100%}
.range output{font-family:var(--mono);font-size:12px;text-align:right}
.check{display:flex;gap:8px;align-items:center;font-size:14px;font-weight:700}
.check input{width:18px;height:18px;accent-color:var(--ok)}
.imggrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:14px}
.imgcard{border:1px solid var(--line);border-radius:10px;overflow:hidden;background:var(--surface);display:flex;flex-direction:column}
.imgcard img{width:100%;aspect-ratio:16/10;object-fit:cover;background:var(--chip);display:block}
.imgcard .b{padding:10px;display:flex;flex-direction:column;gap:8px}
.imgcard .meta{font-size:12px;color:var(--muted);font-family:var(--mono)}
.secrow{display:grid;grid-template-columns:minmax(0,1fr) 90px auto;gap:8px;align-items:center}
.problems{margin:0;padding-left:20px}
.problems a{color:var(--bad)}
.hintline{margin:0;font-size:14px;color:var(--muted)}
.loading{padding:40px 0;color:var(--muted)}

/* ---------- Server pages: identity, status, login, results ---------- */
.idgrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:14px;max-width:640px}
.linkbox{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.linkbox code{font-family:var(--mono);font-size:13px;background:var(--surface);border:1px solid var(--line);border-radius:6px;padding:6px 8px;overflow-wrap:anywhere;min-width:0}
a.btn{display:inline-block;text-decoration:none}
.login{max-width:420px;margin:8vh auto 0}
.tabs{display:flex;flex-wrap:wrap;gap:4px}
.tab{border:0;background:none;padding:8px 14px;border-radius:8px;font-weight:700;cursor:pointer;color:var(--muted)}
.tab[aria-current="true"]{background:var(--accent-soft);color:var(--ink)}
.tab .count{display:inline-block;min-width:20px;padding:0 6px;margin-left:6px;border-radius:999px;background:var(--warn);color:var(--surface);font-size:12px;line-height:20px;font-variant-numeric:tabular-nums}
.toolbar{display:flex;flex-wrap:wrap;gap:10px;align-items:end}
.toolbar .in{width:auto;min-width:200px}
.tablewrap{overflow-x:auto;border:1px solid var(--line);border-radius:10px;background:var(--surface)}
table.results{border-collapse:collapse;width:100%;font-size:14px;font-variant-numeric:tabular-nums}
table.results th,table.results td{text-align:left;padding:10px 12px;border-bottom:1px solid var(--line);white-space:nowrap}
table.results th{font-family:var(--mono);font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);font-weight:500;background:var(--bg)}
table.results tr:last-child td{border-bottom:0}
table.results tr.row{cursor:pointer}
table.results tr.row:hover td{background:var(--chip)}
table.results td.student{white-space:normal;min-width:180px}
table.results td.student span{display:block;color:var(--muted);font-size:13px}
table.results .num{text-align:right}
.pill.warn{background:var(--warn-bg);color:var(--warn)}
.pill.info{background:var(--accent-soft);color:var(--accent)}
.detail td.ans{white-space:normal;min-width:160px}
.verify{max-width:640px}
.verify h1{font-family:var(--display);font-weight:400;font-size:clamp(28px,5vw,40px);margin:8px 0 12px;line-height:1.1}
.verify .ok{display:inline-block;font-family:var(--mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;background:var(--ok-bg);color:var(--ok);padding:4px 10px;border-radius:999px;margin:0}
.verify dl{display:grid;grid-template-columns:auto 1fr;gap:6px 16px;margin:20px 0 0}
.verify dt{font-family:var(--mono);font-size:12px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);padding-top:3px}
.verify dd{margin:0}

@media (max-width:900px){
  .app,.ed{grid-template-columns:minmax(0,1fr)}
  nav.index{position:static;padding:6px;overflow-x:auto;max-height:none}
  nav.index li.sec{display:none}
  nav.index ol{flex-direction:row;gap:3px;width:max-content}
  .qbtn{grid-template-columns:auto auto;gap:5px;padding:7px 9px}
  .qbtn .t{display:none}
  li.end{margin-top:0;border-top:0;padding-top:0;border-left:1px solid var(--line);padding-left:3px}
  .ed-side{position:static;max-height:320px}
  .zwrap{grid-template-columns:minmax(0,1fr)}
}
@media (prefers-reduced-motion:reduce){*{transition:none!important}}