:root {
  --bg: #f4f6f9;
  --panel: #ffffff;
  --ink: #1b2430;
  --muted: #5d6b7a;
  --line: #dde3ea;
  --brand: #1f5e8c;
  --brand-ink: #ffffff;
  --ok: #2e7d32;
  --ok-bg: #e6f4e7;
  --warn: #9a5b00;
  --warn-bg: #fff3dc;
  --bad: #b3261e;
  --bad-bg: #fdecea;
  --info-bg: #e8f1f8;
  --marker: #d32f2f;
  --radius: 10px;
  --shadow: 0 1px 2px rgba(16, 24, 40, .06), 0 1px 3px rgba(16, 24, 40, .08);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--ink);
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); }
button, input, select, textarea { font: inherit; }
h1, h2, h3 { margin: 0 0 .5rem; line-height: 1.25; }
h2 { font-size: 1.2rem; }
h3 { font-size: 1rem; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }
.hidden { display: none !important; }

/* ---- shell ---- */
.top {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; gap: 1rem; flex-wrap: wrap;
  padding: .6rem 1rem; background: var(--brand); color: var(--brand-ink);
}
.top .title { font-weight: 700; margin-right: auto; }
.top nav { display: flex; gap: .25rem; flex-wrap: wrap; }
.top nav button {
  border: 0; background: transparent; color: var(--brand-ink); opacity: .8;
  padding: .4rem .8rem; border-radius: 999px; cursor: pointer;
}
.top nav button[aria-current="page"] { background: rgba(255, 255, 255, .18); opacity: 1; font-weight: 600; }
.who { font-size: .85rem; opacity: .9; }
main { max-width: 1400px; margin: 0 auto; padding: 1rem; }

.btn {
  display: inline-flex; align-items: center; gap: .35rem;
  border: 1px solid var(--line); background: var(--panel); color: var(--ink);
  padding: .45rem .85rem; border-radius: 8px; cursor: pointer; white-space: nowrap;
}
.btn:hover { border-color: #b9c4d0; }
.btn.primary { background: var(--brand); border-color: var(--brand); color: #fff; }
.btn.ok { background: var(--ok); border-color: var(--ok); color: #fff; }
.btn.bad { background: var(--bad); border-color: var(--bad); color: #fff; }
.btn.ghost-light { background: transparent; color: #fff; border-color: rgba(255, 255, 255, .5); }
.btn:disabled { opacity: .5; cursor: default; }
.btn.sm { padding: .25rem .55rem; font-size: .85rem; }

.panel { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 1rem; }
.row { display: flex; gap: .75rem; align-items: center; flex-wrap: wrap; }
.spacer { flex: 1; }
.grid { display: grid; gap: .75rem; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); }
.stack > * + * { margin-top: .75rem; }

.badge { display: inline-block; padding: .1rem .5rem; border-radius: 999px; font-size: .78rem; font-weight: 600; background: var(--info-bg); color: var(--brand); }
.badge.ok { background: var(--ok-bg); color: var(--ok); }
.badge.warn { background: var(--warn-bg); color: var(--warn); }
.badge.bad { background: var(--bad-bg); color: var(--bad); }
.badge.grey { background: #eef1f4; color: var(--muted); }

.alert { padding: .5rem .7rem; border-radius: 8px; font-size: .88rem; }
.alert.technical { background: var(--warn-bg); color: var(--warn); }
.alert.rule { background: var(--bad-bg); color: var(--bad); }
.alert.info { background: var(--info-bg); color: var(--brand); }
.alert b { margin-right: .3rem; }

.error { color: var(--bad); }
.toast { position: fixed; right: 1rem; bottom: 1rem; max-width: 420px; padding: .7rem 1rem; border-radius: 8px; background: var(--ink); color: #fff; box-shadow: var(--shadow); z-index: 50; }

table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: .45rem .5rem; border-bottom: 1px solid var(--line); vertical-align: top; font-size: .9rem; }
th { color: var(--muted); font-weight: 600; font-size: .8rem; text-transform: uppercase; letter-spacing: .03em; }
tr.clickable { cursor: pointer; }
tr.clickable:hover td { background: #f7f9fb; }
.table-wrap { overflow-x: auto; }

input[type=text], input[type=password], input[type=number], textarea, select {
  border: 1px solid var(--line); border-radius: 8px; padding: .45rem .6rem; background: #fff; color: var(--ink);
}
textarea { width: 100%; min-height: 4rem; }
label.field { display: grid; gap: .25rem; font-size: .88rem; color: var(--muted); }

/* ---- login ---- */
.login { max-width: 380px; margin: 10vh auto; }
.login form { display: grid; gap: .8rem; }

/* ---- invigilation ---- */
.student-card { display: grid; gap: .5rem; }
.student-card.attention { border-color: var(--bad); box-shadow: 0 0 0 2px var(--bad-bg); }
.student-card .name { font-weight: 600; }
.kv { display: grid; grid-template-columns: auto 1fr; gap: .15rem .6rem; font-size: .85rem; }
.kv dt { color: var(--muted); }
.kv dd { margin: 0; }
.request { border: 1px solid var(--line); border-radius: 8px; padding: .5rem; display: grid; gap: .4rem; }
.request.pending { border-color: var(--bad); background: #fffafa; }
.pending-strip { border-left: 4px solid var(--bad); }
.stats { display: flex; gap: .5rem; flex-wrap: wrap; }
.stat { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: .5rem .9rem; min-width: 110px; }
.stat b { display: block; font-size: 1.4rem; }

/* ---- marking ---- */
.marking { display: grid; grid-template-columns: 300px 1fr; gap: 1rem; align-items: start; }
@media (max-width: 900px) { .marking { grid-template-columns: 1fr; } }
.qlist { position: sticky; top: 4rem; display: grid; gap: .5rem; max-height: calc(100vh - 5rem); overflow: auto; }
.qitem { border: 1px solid var(--line); border-radius: 8px; padding: .5rem; background: var(--panel); cursor: pointer; }
.qitem.active { border-color: var(--brand); box-shadow: 0 0 0 2px var(--info-bg); }
.qitem .row { gap: .4rem; }
.qitem input[type=number] { width: 4.5rem; }
.total { font-size: 1.3rem; font-weight: 700; }
.toolbar { display: flex; gap: .35rem; flex-wrap: wrap; align-items: center; position: sticky; top: 3.4rem; z-index: 5; background: var(--bg); padding: .4rem 0; }
.toolbar .btn[aria-pressed="true"] { border-color: var(--marker); color: var(--marker); font-weight: 600; background: #fff5f5; }
.page-wrap { position: relative; background: #fff; border: 1px solid var(--line); border-radius: 6px; overflow: hidden; margin-bottom: .75rem; }
.page-wrap canvas { display: block; width: 100%; height: auto; touch-action: none; }
.page-label { position: absolute; top: .3rem; left: .5rem; font-size: .75rem; color: var(--muted); background: rgba(255,255,255,.85); padding: 0 .3rem; border-radius: 4px; }
.typed { white-space: pre-wrap; background: #fbfcfd; border: 1px solid var(--line); border-radius: 6px; padding: .7rem; font-family: ui-serif, Georgia, serif; }
.guide { background: #f6f9ee; border: 1px solid #dbe6c4; border-radius: 6px; padding: .6rem; font-size: .9rem; }
.advisory { border: 1px solid var(--warn); background: #fffbf2; border-radius: 8px; padding: .75rem; display: grid; gap: .5rem; }
.advisory.done { border-color: var(--line); background: #fff; }
.compare td.num { text-align: center; font-variant-numeric: tabular-nums; }
.diff { color: var(--bad); font-weight: 700; }

dialog { border: 0; border-radius: var(--radius); box-shadow: 0 10px 40px rgba(0,0,0,.25); max-width: 480px; width: calc(100% - 2rem); }
dialog::backdrop { background: rgba(15, 23, 42, .45); }
dialog form { display: grid; gap: .75rem; }