/* Unlearn: a calm, legible "lab notebook" look. Semantic graph colours are the only loud colours on the page. */

:root {
  --bg: #f6f5f1;
  --paper: #ffffff;
  --ink: #1b1d22;
  --ink-2: #3c4049;
  --muted: #656973;
  --line: #e4e2dc;
  --line-2: #d6d3cb;
  --accent: #2f3ab8;       /* interaction: buttons, focus, "asked now" */
  --accent-soft: #eceefc;
  --mis: #d2453f;          /* misconception */
  --mis-soft: #fbeceb;
  --ok: #2e9b62;           /* mastered */
  --ok-soft: #e8f5ee;
  --root: #e3a33b;         /* root cause */
  --root-soft: #fdf3e2;
  --grey: #c9cbd1;
  /* every other colour on the page, so the dark palette below can swap them all */
  --topbar-bg: rgba(246, 245, 241, .92);
  --tabs-bg: #ecebe5;
  --field-bg: #fcfcfa;
  --soft-bg: #fdfcf9;
  --key-bg: #efeee9;
  --hover-bg: #f4f3ef;
  --bot-bg: #f2f1ec;
  --pre-bg: #f6f5f1;
  --grid-dot: #ebe9e3;
  --btn-hover-line: #bdb9ae;
  --on-ink: #ffffff;           /* text on ink-coloured buttons and bubbles */
  --primary-hover: #2c2f37;
  --on-ok: #ffffff;
  --ok-button: #23784a;       /* approve: white text needs a deeper green for AA */
  --ok-ink: #1f7a4b;
  --mis-ink: #a8302b;
  --chip-ink: #9a2d28;
  --root-ink: #95620f;
  --root-edge: #b97a12;
  --banner-line: #f0d9ae;
  --banner-ink: #8a5a0c;
  --reject-line: #efc9c6;
  --scrim: rgba(27, 29, 34, .18);
  --drawer-shadow: -12px 0 40px rgba(0,0,0,.08);
  --tip-bg: #1b1d22;
  --tip-ink: #ffffff;
  /* the prerequisite graph (Cytoscape reads these, and restyles when the theme changes) */
  --cy-node-bg: #f1f1ee;
  --cy-node-line: #c9cbd1;
  --cy-node-ink: #3c4049;
  --cy-target: #1b1d22;
  --cy-attempted: #9aa0ab;
  --cy-mastered-bg: #e3f3ea;
  --cy-mastered-ink: #17603b;
  --cy-root-bg: #fdf0d8;
  --cy-root-ink: #6b4405;
  --cy-mis-bg: #fbeceb;
  --cy-mis-ink: #9a2d28;
  --cy-mis-strong-ink: #ffffff;
  --cy-more-bg: #ffffff;
  --cy-seen: #e8a4a1;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(27, 29, 34, .05), 0 6px 24px rgba(27, 29, 34, .04);
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
  --sans: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  color-scheme: light;
}

/* Dark palette: same roles, warm greys; text pairs meet WCAG AA on --paper and --bg. The head script sets
   data-theme from the saved choice or prefers-color-scheme before the page paints. */
:root[data-theme="dark"] {
  --bg: #141518;
  --paper: #1d1f23;
  --ink: #eceae4;
  --ink-2: #cbc9c2;
  --muted: #a3a6ae;
  --line: #2e3136;
  --line-2: #42464d;
  --accent: #9aa3ff;
  --accent-soft: #262a4d;
  --mis: #ee6b63;
  --mis-soft: #3b2221;
  --ok: #4fc58a;
  --ok-soft: #1a3226;
  --root: #f0b44f;
  --root-soft: #392c16;
  --grey: #5d616a;
  --topbar-bg: rgba(20, 21, 24, .9);
  --tabs-bg: #26282d;
  --field-bg: #17181c;
  --soft-bg: #212328;
  --key-bg: #2c2f35;
  --hover-bg: #26282d;
  --bot-bg: #272a30;
  --pre-bg: #16171a;
  --grid-dot: #2a2d32;
  --btn-hover-line: #5b5f67;
  --on-ink: #141518;
  --primary-hover: #d5d3cc;
  --on-ok: #0c2016;
  --ok-button: #4fc58a;
  --ok-ink: #7fd9a8;
  --mis-ink: #f5a29c;
  --chip-ink: #f5a29c;
  --root-ink: #f2c47c;
  --root-edge: #f6c66e;
  --banner-line: #5a4523;
  --banner-ink: #f2c47c;
  --reject-line: #6b3330;
  --scrim: rgba(0, 0, 0, .45);
  --drawer-shadow: -12px 0 40px rgba(0,0,0,.45);
  --tip-bg: #2e3137;
  --tip-ink: #f3f2ed;
  --cy-node-bg: #24262b;
  --cy-node-line: #575b63;
  --cy-node-ink: #d9d7d0;
  --cy-target: #eceae4;
  --cy-attempted: #8b909a;
  --cy-mastered-bg: #183024;
  --cy-mastered-ink: #8fe0b4;
  --cy-root-bg: #3d2f15;
  --cy-root-ink: #f6d293;
  --cy-mis-bg: #3b2221;
  --cy-mis-ink: #f5a29c;
  --cy-mis-strong-ink: #240c0a;
  --cy-more-bg: #1d1f23;
  --cy-seen: #a5524d;
  --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 6px 24px rgba(0, 0, 0, .25);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.5 var(--sans);
  -webkit-font-smoothing: antialiased;
}
[hidden] { display: none !important; }
code { font-family: var(--mono); font-size: .92em; }
button, input, select, textarea { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; gap: 24px;
  padding: 12px 28px;
  background: var(--topbar-bg);
  backdrop-filter: saturate(1.2) blur(8px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: baseline; gap: 12px; min-width: 0; }
.mark { display: inline-grid; grid-template-columns: repeat(2, 8px); gap: 3px; transform: translateY(1px); }
.mark i { width: 8px; height: 8px; border-radius: 50%; background: var(--grey); }
.mark i:nth-child(1) { background: var(--root); grid-column: 1 / span 2; justify-self: center; }
.mark i:nth-child(3) { background: var(--mis); }
.wordmark { font-family: var(--serif); font-size: 24px; font-weight: 600; letter-spacing: -.01em; }
.tagline { color: var(--muted); font-size: 13px; white-space: nowrap; }
.tabs { display: flex; gap: 4px; margin-left: auto; background: var(--tabs-bg); padding: 4px; border-radius: 999px; }
.tab {
  border: 0; background: transparent; padding: 6px 16px; border-radius: 999px; cursor: pointer;
  color: var(--ink-2); font-weight: 500;
}
.tab[aria-selected="true"] { background: var(--paper); color: var(--ink); box-shadow: 0 1px 2px rgba(0,0,0,.12); }
.class-pick { display: flex; align-items: center; gap: 8px; margin: 0; font-size: 13px; color: var(--muted); font-weight: 500; letter-spacing: 0; }
.class-pick select { width: auto; padding: 5px 10px; border-radius: 999px; background: var(--paper); font-family: var(--mono); font-size: 13px; }
.scoreboard .scores { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; }
.score { border: 1px solid var(--line); border-radius: 12px; padding: 10px 14px; background: var(--soft-bg); cursor: pointer; text-align: left; }
.score.active { border-color: var(--ink); box-shadow: inset 0 0 0 1px var(--ink); }
.score .who { font-weight: 600; }
.score .pct { font-family: var(--serif); font-size: 30px; font-weight: 600; line-height: 1.1; }
.score .frac { color: var(--muted); font-size: 13px; }
.q-score { text-transform: none; letter-spacing: 0; font-weight: 500; color: var(--ink-2); }
.status { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 13px; white-space: nowrap; }
.status .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--grey); }
.status.ok .dot { background: var(--ok); box-shadow: 0 0 0 3px var(--ok-soft); }
.status.bad .dot { background: var(--mis); }

main { padding: 24px 28px 48px; max-width: 1880px; margin: 0 auto; }

/* ---------- cards & common ---------- */
.card {
  background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 20px 22px;
}
.card + .card, .banner + .card, .card + .banner { margin-top: 16px; }
.card-kicker {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  font-size: 12px; letter-spacing: .06em; text-transform: uppercase; color: var(--muted); font-weight: 600;
  margin-bottom: 10px;
}
.card-kicker .muted { text-transform: none; letter-spacing: 0; font-weight: 400; }
.muted { color: var(--muted); }
.agent-chip {
  display: inline-flex; align-items: center; gap: 6px; padding: 2px 9px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent); font-size: 11px; letter-spacing: .04em;
}
.agent-chip.tutor { background: var(--ok-soft); color: var(--ok-ink); }
.agent-chip.teacher { background: var(--root-soft); color: var(--root-ink); }
.subhead { font-size: 12px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); font-weight: 600; margin: 18px 0 6px; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border: 1px solid var(--line-2); background: var(--paper); color: var(--ink);
  padding: 9px 16px; border-radius: 10px; cursor: pointer; font-weight: 550;
  transition: background .15s, border-color .15s, transform .05s;
}
.btn:hover { border-color: var(--btn-hover-line); }
.btn:active { transform: translateY(1px); }
.btn.primary { background: var(--ink); border-color: var(--ink); color: var(--on-ink); }
.btn.primary:hover { background: var(--primary-hover); }
.btn.link { border: 0; background: none; padding: 4px 0; color: var(--accent); font-weight: 500; }
.btn.icon { width: 36px; height: 36px; padding: 0; border-radius: 50%; }
.btn[disabled] { opacity: .5; cursor: progress; }
.btn.approve { background: var(--ok-button); border-color: var(--ok-button); color: var(--on-ok); }
.btn.reject { color: var(--mis); border-color: var(--reject-line); }

select, input[type="text"], input:not([type]), textarea {
  width: 100%; border: 1px solid var(--line-2); background: var(--field-bg); border-radius: 10px; padding: 9px 12px;
}
textarea { resize: vertical; min-height: 56px; }
label { font-size: 12px; color: var(--muted); font-weight: 600; letter-spacing: .03em; display: block; margin-bottom: 4px; }

/* ---------- student view ---------- */
.student-grid { display: grid; grid-template-columns: minmax(380px, 520px) minmax(0, 1fr); gap: 20px; align-items: start; }
.setup { display: grid; grid-template-columns: 1fr; gap: 12px; }
.setup .field.grow select { text-overflow: ellipsis; }
.setup-actions { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.toggle { display: inline-flex; align-items: center; gap: 8px; margin: 0; color: var(--ink-2); font-size: 14px; font-weight: 500; letter-spacing: 0; cursor: pointer; }
.toggle input { width: 16px; height: 16px; accent-color: var(--accent); }

.banner {
  border-radius: var(--radius); padding: 14px 18px; border: 1px solid var(--banner-line); background: var(--root-soft);
}
.banner-kicker { font-family: var(--serif); font-style: italic; font-size: 17px; color: var(--banner-ink); margin-bottom: 2px; }
.banner-body { color: var(--ink-2); }

.q-text { font-family: var(--serif); font-weight: 600; font-size: 25px; line-height: 1.3; margin: 2px 0 16px; letter-spacing: -.005em; }
.q-text.small { font-size: 20px; }
#q-progress { margin-left: auto; text-transform: none; letter-spacing: 0; font-weight: 500; }
.options { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.option {
  display: flex; align-items: center; gap: 12px; text-align: left;
  border: 1.5px solid var(--line-2); background: var(--field-bg); border-radius: 12px; padding: 12px 14px;
  cursor: pointer; font-size: 17px; min-height: 54px; transition: border-color .15s, background .15s;
}
.option:hover { border-color: var(--accent); background: var(--accent-soft); }
.option .key {
  flex: none; width: 28px; height: 28px; border-radius: 8px; display: grid; place-items: center;
  background: var(--key-bg); font-weight: 700; font-size: 13px; color: var(--ink-2);
}
.option.picked.right { border-color: var(--ok); background: var(--ok-soft); }
.option.picked.wrong { border-color: var(--mis); background: var(--mis-soft); }
.options.locked .option { pointer-events: none; }
.explain { margin-top: 14px; }
.explain summary { cursor: pointer; color: var(--ink-2); font-weight: 500; }
.explain .optional { color: var(--muted); font-weight: 400; font-size: 13px; margin-left: 4px; }
.explain textarea { margin-top: 8px; }
.q-foot { margin-top: 10px; }
.feedback { margin-top: 10px; min-height: 0; font-size: 14px; }
.feedback .tag { display: inline-block; padding: 1px 8px; border-radius: 999px; font-size: 12px; font-weight: 600; margin-right: 6px; }
.feedback .tag.right { background: var(--ok-soft); color: var(--ok-ink); }
.feedback .tag.wrong { background: var(--mis-soft); color: var(--mis-ink); }
.feedback .heard { color: var(--muted); margin-top: 4px; }

.dx-root { font-family: var(--serif); font-size: 22px; font-weight: 600; line-height: 1.3; }
.dx-root .ev { display: block; font-family: var(--sans); font-size: 13px; color: var(--muted); font-weight: 500; margin-top: 4px; }
.chain { list-style: none; margin: 14px 0; padding: 0; border-left: 2px solid var(--root); }
.chain li { position: relative; padding: 4px 0 4px 16px; color: var(--ink-2); font-size: 14px; }
.chain li::before { content: ""; position: absolute; left: -6px; top: 11px; width: 10px; height: 10px; border-radius: 50%; background: var(--paper); border: 2px solid var(--grey); }
.chain li:last-child { color: var(--ink); font-weight: 600; }
.chain li:last-child::before { background: var(--root); border-color: var(--root-edge); }
.dx-message { color: var(--muted); font-size: 14px; margin: 0 0 14px; }

.tutor-explain p { margin: 0 0 8px; }
.tutor-explain ol { margin: 6px 0 0; padding-left: 22px; color: var(--ink-2); }
.tutor-explain li { margin: 4px 0; }

/* graph */
.graph-card { padding: 16px 18px 12px; position: relative; }
.graph-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; flex-wrap: wrap; }
.graph-title { font-family: var(--serif); font-size: 19px; font-weight: 600; max-width: 760px; }
.legend { display: flex; gap: 14px; flex-wrap: wrap; list-style: none; margin: 4px 0 0; padding: 0; font-size: 12.5px; color: var(--muted); }
.legend li { display: flex; align-items: center; gap: 6px; }
.sw { width: 12px; height: 12px; border-radius: 4px; display: inline-block; background: var(--grey); }
.sw.mis { background: var(--mis); border-radius: 50%; }
.sw.mastered { background: var(--ok); }
.sw.root { background: var(--root); outline: 2px solid var(--root-edge); outline-offset: 0; }
.sw.asked { background: var(--paper); outline: 2px solid var(--accent); }
.cy { height: min(62vh, 640px); min-height: 380px; margin-top: 8px; border-radius: 10px; background:
  radial-gradient(circle at 1px 1px, var(--grid-dot) 1px, transparent 0) 0 0 / 22px 22px; }
.graph-empty { position: absolute; inset: 120px 24px 24px; display: grid; place-items: center; color: var(--muted); text-align: center; pointer-events: none; }

/* receipts list */
.steps { list-style: none; margin: 0; padding: 0; max-height: 300px; overflow: auto; }
.steps li { border-top: 1px solid var(--line); }
.steps li:first-child { border-top: 0; }
.steps .step-group { font-size: 12px; color: var(--muted); padding: 10px 2px 4px; font-weight: 600; letter-spacing: .03em; }
.steps button {
  width: 100%; display: grid; grid-template-columns: 92px 150px minmax(0, 1fr); gap: 10px; align-items: center;
  text-align: left; padding: 7px 4px; border: 0; background: none; cursor: pointer; border-radius: 6px;
}
.steps button:hover { background: var(--hover-bg); }
.steps .tool { font-family: var(--mono); font-size: 13px; color: var(--ink); }
.steps .q { font-family: var(--mono); font-size: 12px; color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.steps .said { font-size: 13px; color: var(--ink-2); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* ---------- teacher view ---------- */
.view-title { font-family: var(--serif); font-size: 30px; margin: 0; letter-spacing: -.01em; }
.teacher-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 16px; margin-bottom: 18px; flex-wrap: wrap; }
.teacher-head p { margin: 2px 0 0; }
.teacher-actions { display: flex; gap: 10px; flex-wrap: wrap; }
.teacher-grid {
  display: grid; gap: 16px;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  grid-template-areas:
    "prop prop prop prop prop coh coh coh coh chat chat chat"
    "key key key key bri bri bri bri bri chat chat chat";
}
.teacher-grid .card + .card { margin-top: 0; }
.t-proposals { grid-area: prop; } .t-cohorts { grid-area: coh; } .t-keystones { grid-area: key; }
.t-bridges { grid-area: bri; } .t-chat { grid-area: chat; display: flex; flex-direction: column; min-height: 520px; }
.receipt-link { margin-left: auto; border: 0; background: none; color: var(--accent); cursor: pointer; font-size: 12px; text-transform: none; letter-spacing: 0; font-weight: 500; }
.list { display: grid; gap: 10px; }
.t-proposals .list, .t-cohorts .list { max-height: 560px; overflow: auto; padding-right: 4px; }
.empty { color: var(--muted); font-size: 14px; padding: 6px 0; }
.proposal { border: 1px solid var(--line); border-radius: 12px; padding: 14px; display: grid; gap: 8px; background: var(--soft-bg); }
.proposal .p-head { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.kind { font-family: var(--mono); font-size: 12px; padding: 2px 8px; border-radius: 6px; background: var(--key-bg); }
.proposal .reason { color: var(--ink-2); font-size: 14px; }
.proposal .p-actions { display: flex; gap: 8px; }
.proposal.done { opacity: .6; }
.cohort { display: flex; flex-wrap: wrap; gap: 6px; padding: 10px 12px; border: 1px dashed var(--line-2); border-radius: 12px; }
.chip { padding: 3px 10px; border-radius: 999px; background: var(--mis-soft); color: var(--chip-ink); font-size: 13px; font-weight: 500; }
.ranked { list-style: none; padding: 0; margin: 0; counter-reset: r; }
.ranked li { counter-increment: r; display: grid; grid-template-columns: 26px minmax(0, 1fr); gap: 8px; padding: 7px 0; border-top: 1px solid var(--line); font-size: 14px; }
.ranked li:first-child { border-top: 0; }
.ranked li::before { content: counter(r); color: var(--muted); font-variant-numeric: tabular-nums; font-weight: 600; }
.ranked .bar { height: 4px; border-radius: 4px; background: var(--root); margin-top: 5px; opacity: .8; }
.ranked.bridges .bar { background: var(--accent); }
.chat-log { flex: 1; overflow: auto; display: flex; flex-direction: column; gap: 10px; padding: 4px 2px 12px; max-height: 560px; }
.msg { max-width: 92%; padding: 10px 14px; border-radius: 14px; font-size: 14.5px; }
.msg.me { align-self: flex-end; background: var(--ink); color: var(--on-ink); border-bottom-right-radius: 4px; }
.msg.bot { align-self: flex-start; background: var(--bot-bg); border-bottom-left-radius: 4px; }
.msg .meta { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 8px; }
.msg .meta button { border: 1px solid var(--line-2); background: var(--paper); border-radius: 999px; padding: 1px 8px; font-family: var(--mono); font-size: 11px; cursor: pointer; }
.chat-form { display: flex; gap: 8px; }
.chat-examples { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; margin: 0 0 8px; font-size: 13px; }
.chat-example { border: 1px solid var(--line-2); background: var(--paper); color: var(--ink-2); border-radius: 999px;
  padding: 3px 10px; font-size: 12.5px; cursor: pointer; }
.chat-example:hover { border-color: var(--btn-hover-line); color: var(--ink); }

/* ---------- eval ---------- */
#eval-results table { border-collapse: collapse; margin-top: 16px; background: var(--paper); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
#eval-results th, #eval-results td { padding: 8px 14px; border-bottom: 1px solid var(--line); text-align: right; font-variant-numeric: tabular-nums; }
#eval-results th:first-child, #eval-results td:first-child { text-align: left; font-family: var(--mono); font-size: 13px; }
#eval-results h2 { font-family: var(--serif); margin: 28px 0 0; }
#eval-results table.eval td { text-align: left; font-family: var(--sans); font-size: 14px; }
#eval-results table.eval td:first-child { font-family: var(--sans); font-weight: 500; }
#eval-results table.eval .muted { font-size: 12px; margin-left: 4px; }

/* ---------- drawer ---------- */
.drawer {
  position: fixed; top: 0; right: 0; bottom: 0; width: min(720px, 100vw); z-index: 40;
  background: var(--paper); border-left: 1px solid var(--line); box-shadow: var(--drawer-shadow);
  transform: translateX(105%); transition: transform .22s ease; display: flex; flex-direction: column;
}
.drawer.open { transform: none; }
.drawer-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 12px; padding: 18px 22px; border-bottom: 1px solid var(--line); }
.drawer-head h2 { font-family: var(--mono); font-size: 19px; margin: 0; }
.drawer-body { overflow: auto; padding: 8px 22px 32px; }
.drawer-body h3 { font-size: 12px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); margin: 18px 0 6px; }
.drawer-body pre {
  margin: 0; padding: 12px 14px; background: var(--pre-bg); border: 1px solid var(--line); border-radius: 10px;
  font: 12.5px/1.55 var(--mono); white-space: pre-wrap; word-break: break-word; max-height: 420px; overflow: auto;
}
.drawer-body .qname { display: inline-block; font-family: var(--mono); font-size: 12px; padding: 2px 8px; border-radius: 6px; background: var(--accent-soft); color: var(--accent); margin-bottom: 6px; }
.drawer-body .said { font-family: var(--serif); font-size: 17px; line-height: 1.5; white-space: pre-line; }
.scrim { position: fixed; inset: 0; background: var(--scrim); z-index: 30; }

/* ---------- first-visit guide, captions, legend help, theme toggle ---------- */
.guide { margin-bottom: 20px; display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 6px 24px; align-items: start; }
.guide h2 { font-family: var(--serif); font-size: 21px; margin: 0 0 4px; letter-spacing: -.005em; }
.guide .lede { margin: 0; color: var(--ink-2); max-width: 820px; }
.guide ol { grid-column: 1 / -1; margin: 10px 0 0; padding: 0; list-style: none; counter-reset: g;
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.guide li { counter-increment: g; position: relative; padding: 12px 14px 12px 46px; border: 1px solid var(--line); border-radius: 12px;
  background: var(--soft-bg); color: var(--ink-2); font-size: 14px; }
.guide li::before { content: counter(g); position: absolute; left: 14px; top: 11px; width: 22px; height: 22px; border-radius: 50%;
  display: grid; place-items: center; background: var(--ink); color: var(--on-ink); font-size: 12px; font-weight: 700; }
.guide li strong { color: var(--ink); }
.guide code, .card-caption code, .legend-help-text code { font-size: .88em; padding: 0 4px; border-radius: 4px; background: var(--key-bg); color: var(--ink-2); }
.guide-actions { display: flex; gap: 8px; align-items: center; }
.guide a.btn { text-decoration: none; }
.card-caption { margin: -4px 0 12px; color: var(--muted); font-size: 13.5px; line-height: 1.45; }
.eval-caption { max-width: 880px; color: var(--ink-2); margin: 6px 0 0; }
.legend-help { width: 20px; height: 20px; padding: 0; border-radius: 50%; border: 1px solid var(--line-2); background: var(--paper);
  color: var(--muted); font-size: 12px; font-weight: 700; line-height: 1; cursor: pointer; }
.legend-help:hover, .legend-help[aria-expanded="true"] { color: var(--ink); border-color: var(--ink-2); }
.legend-help-text { flex-basis: 100%; max-width: 760px; padding: 12px 14px;
  background: var(--paper); border: 1px solid var(--line-2); border-radius: 12px; box-shadow: var(--shadow); font-size: 13.5px; color: var(--ink-2); }
.legend-help-text p { margin: 0 0 6px; } .legend-help-text p:last-child { margin: 0; }
.theme-toggle { width: 34px; height: 34px; flex: none; padding: 0; border-radius: 50%; border: 1px solid var(--line-2); background: var(--paper);
  color: var(--ink-2); cursor: pointer; display: grid; place-items: center; }
.theme-toggle:hover { color: var(--ink); border-color: var(--btn-hover-line); }
.theme-toggle svg { width: 17px; height: 17px; }
.theme-toggle .moon { display: none; }
:root[data-theme="dark"] .theme-toggle .sun { display: none; }
:root[data-theme="dark"] .theme-toggle .moon { display: block; }
.topbar { flex-wrap: nowrap; }
.status { min-width: 0; }
.status .label { overflow: hidden; text-overflow: ellipsis; }

/* ---------- responsive ---------- */
@media (max-width: 1280px) {
  .teacher-grid { grid-template-columns: 1fr 1fr; grid-template-areas: "prop coh" "key bri" "chat chat"; }
}
@media (max-width: 960px) {
  .student-grid { grid-template-columns: 1fr; }
  .tagline { display: none; }
  .guide ol { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .topbar { padding: 10px 16px; gap: 12px; flex-wrap: wrap; }
  .tabs { margin-left: 0; order: 3; width: 100%; justify-content: center; }
  .status .label { display: none; }
  .class-pick span { display: none; }
  .status { margin-left: auto; }
  main { padding: 16px 16px 40px; }
  .card { padding: 16px; }
  .options { grid-template-columns: 1fr; }
  .q-text { font-size: 21px; }
  .cy { height: 380px; }
  .teacher-grid { grid-template-columns: 1fr; grid-template-areas: "prop" "coh" "key" "bri" "chat"; }
  .steps button { grid-template-columns: 80px minmax(0, 1fr); }
  .steps .q { display: none; }
  .topbar { flex-wrap: wrap; }
  .guide { grid-template-columns: 1fr; }
  .student-grid { grid-template-columns: minmax(0, 1fr); }
  .setup-actions { flex-wrap: wrap; }
  .teacher-actions .btn { flex: 1 1 auto; }
  #eval-results table { display: block; max-width: 100%; overflow-x: auto; }
  .legend { gap: 10px; }
}

#eval-results .footnote { margin-top: 32px; color: var(--muted); font-size: 14px; }
#eval-results .footnote summary { cursor: pointer; }