/* ============================================================
   Stat 20 Quiz 2 Trainer — design system
   Direction: "course notes made interactive."
   Cool academic paper, Berkeley-blue ink, California-gold
   highlighter. Tickets-from-a-box as the mastery motif.
   ============================================================ */

:root {
  /* paper & ink */
  --paper: #f7f9fc;
  --card: #ffffff;
  --card-2: #f0f4f9;
  --ink: #182635;
  --ink-soft: #46586c;
  --ink-faint: #7b8a9b;
  --line: #dbe3ec;
  --line-strong: #b9c6d4;

  /* identity */
  --blue: #0e3a66;        /* berkeley ink */
  --blue-bright: #1f5f9e;
  --blue-wash: #e3edf7;
  --gold: #fdb515;        /* california gold — the highlighter */
  --gold-soft: #fff3d1;
  --gold-ink: #7a5a00;

  /* semantics */
  --good: #2e7d4f;
  --good-wash: #e2f2e8;
  --bad: #c0392b;
  --bad-wash: #fbe9e6;
  --warn: #a06a00;
  --warn-wash: #fdf3dc;

  /* type */
  --font-display: "Iowan Old Style", "Palatino", "Book Antiqua", Georgia, serif;
  --font-ui: "Avenir Next", "Avenir", "Seravek", -apple-system, system-ui, "Segoe UI", sans-serif;
  --font-mono: "SF Mono", ui-monospace, Menlo, Consolas, monospace;

  /* geometry */
  --r-sm: 6px;
  --r-md: 10px;
  --r-lg: 16px;
  --shadow-1: 0 1px 2px rgba(14, 33, 56, 0.06), 0 2px 8px rgba(14, 33, 56, 0.05);
  --shadow-2: 0 2px 6px rgba(14, 33, 56, 0.09), 0 10px 28px rgba(14, 33, 56, 0.08);
  --maxw: 1080px;

  color-scheme: light;
}

:root[data-theme="dark"] {
  --paper: #0d141d;
  --card: #15202c;
  --card-2: #1b2836;
  --ink: #e7edf4;
  --ink-soft: #a8b8c8;
  --ink-faint: #71839a;
  --line: #263646;
  --line-strong: #3a4e63;

  --blue: #8db8e8;
  --blue-bright: #6aa5e0;
  --blue-wash: #1a2c40;
  --gold: #f5b62d;
  --gold-soft: #3a2f11;
  --gold-ink: #ffd97a;

  --good: #58b183;
  --good-wash: #152b20;
  --bad: #e07766;
  --bad-wash: #3a1d18;
  --warn: #d9a53f;
  --warn-wash: #33270f;

  --shadow-1: 0 1px 2px rgba(0, 0, 0, 0.4), 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-2: 0 2px 6px rgba(0, 0, 0, 0.45), 0 10px 28px rgba(0, 0, 0, 0.4);

  color-scheme: dark;
}

/* ---------- reset & base ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-ui);
  font-size: 16px;
  line-height: 1.55;
  color: var(--ink);
  background: var(--paper);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }
input, select, textarea { font: inherit; color: inherit; }
img, svg { max-width: 100%; display: block; }
h1, h2, h3, h4 { font-family: var(--font-display); line-height: 1.25; font-weight: 600; }
code, .rcode { font-family: var(--font-mono); }

:focus-visible {
  outline: 2.5px solid var(--blue-bright);
  outline-offset: 2px;
  border-radius: 4px;
}

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--blue); color: #fff; padding: 8px 14px; z-index: 100;
  border-radius: 0 0 var(--r-sm) 0;
}
.skip-link:focus { left: 0; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

/* ---------- top bar ---------- */
.topbar {
  background: var(--card);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 50;
  padding-left: env(safe-area-inset-left);
  padding-right: env(safe-area-inset-right);
}
@supports (padding-top: env(safe-area-inset-top)) {
  .topbar { padding-top: env(safe-area-inset-top); }
}
.topbar-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 10px 20px;
  display: flex; align-items: center; gap: 18px;
}
.brand { display: flex; align-items: center; gap: 10px; padding: 4px 6px; border-radius: var(--r-sm); }
.brand-mark { font-size: 20px; }
.brand-text { font-family: var(--font-display); font-size: 17px; color: var(--ink-soft); white-space: nowrap; }
.brand-text strong { color: var(--blue); font-weight: 700; }

.mainnav { display: flex; gap: 4px; margin-left: auto; overflow-x: auto; }
@media (max-width: 720px) {
  .topbar-inner { flex-wrap: wrap; padding: 8px 12px; gap: 8px; }
  .brand { order: 1; }
  .topbar-actions { order: 2; margin-left: auto; }
  .mainnav { order: 3; width: 100%; margin-left: 0; justify-content: space-between; }
  .navbtn { padding: 6px 10px; font-size: 13.5px; flex: 1; text-align: center; }
}
.navbtn {
  padding: 7px 14px; border-radius: 999px; font-weight: 600; font-size: 14.5px;
  color: var(--ink-soft);
}
.navbtn:hover { background: var(--card-2); color: var(--ink); }
.navbtn[aria-current="page"] {
  background: var(--blue); color: #fff;
}
:root[data-theme="dark"] .navbtn[aria-current="page"] { background: var(--blue-wash); color: var(--blue); }

.topbar-actions { display: flex; gap: 6px; }
.iconbtn {
  width: 34px; height: 34px; border-radius: 50%; font-size: 17px;
  display: grid; place-items: center; color: var(--ink-soft);
  border: 1px solid var(--line);
}
.iconbtn:hover { background: var(--card-2); }

/* ---------- layout ---------- */
.app-main { flex: 1; width: 100%; }
#view-root { max-width: var(--maxw); margin: 0 auto; padding: 26px 20px 60px; }
.appfoot {
  text-align: center; padding: 18px; color: var(--ink-faint); font-size: 12.5px;
  border-top: 1px solid var(--line);
}

.view-title { font-size: 26px; color: var(--ink); margin-bottom: 4px; }
.view-sub { color: var(--ink-soft); margin-bottom: 22px; max-width: 68ch; }

/* ---------- cards ---------- */
.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--r-lg); box-shadow: var(--shadow-1);
  padding: 20px;
}
.card + .card { margin-top: 16px; }
.card-title {
  font-size: 18px; margin-bottom: 10px; color: var(--ink);
}
.eyebrow {
  font-family: var(--font-ui); font-size: 11.5px; font-weight: 700;
  letter-spacing: 0.09em; text-transform: uppercase; color: var(--ink-faint);
  margin-bottom: 6px;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px; justify-content: center;
  padding: 9px 18px; border-radius: var(--r-md); font-weight: 600; font-size: 15px;
  border: 1px solid transparent;
  transition: transform 0.06s ease, background 0.12s ease, box-shadow 0.12s ease;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--blue); color: #fff; }
.btn-primary:hover { background: var(--blue-bright); }
:root[data-theme="dark"] .btn-primary { background: var(--blue-bright); color: #08141f; }
:root[data-theme="dark"] .btn-primary:hover { background: var(--blue); }
.btn-gold { background: var(--gold); color: #241a00; }
.btn-gold:hover { filter: brightness(1.05); }
.btn-ghost { border-color: var(--line-strong); color: var(--ink-soft); background: var(--card); }
.btn-ghost:hover { background: var(--card-2); color: var(--ink); }
.btn-danger { background: var(--bad); color: #fff; }
.btn[disabled] { opacity: 0.45; cursor: not-allowed; }
.btn-sm { padding: 5px 12px; font-size: 13.5px; border-radius: 8px; }

/* ---------- tickets (mastery motif) ----------
   Skills render as tickets from a box: perforated left edge,
   punched when mastered. */
.ticket {
  position: relative;
  display: flex; align-items: center; gap: 10px;
  background: var(--card); border: 1px solid var(--line);
  border-left: 4px solid var(--line-strong);
  border-radius: var(--r-md);
  padding: 10px 14px 10px 16px;
  text-align: left; width: 100%;
  transition: box-shadow 0.12s ease, transform 0.06s ease;
}
.ticket::before {
  content: ""; position: absolute; left: -1px; top: 50%; transform: translateY(-50%);
  width: 7px; height: 60%;
  background-image: radial-gradient(circle, var(--paper) 2.1px, transparent 2.3px);
  background-size: 7px 9px; background-repeat: repeat-y; background-position: left center;
}
.ticket:hover { box-shadow: var(--shadow-2); transform: translateY(-1px); }
.ticket .t-name { font-weight: 600; font-size: 14.5px; flex: 1; }
.ticket .t-meta { font-size: 12px; color: var(--ink-faint); }
.ticket.m-0 { border-left-color: var(--line-strong); }
.ticket.m-1 { border-left-color: var(--bad); }
.ticket.m-2 { border-left-color: var(--warn); }
.ticket.m-3 { border-left-color: var(--blue-bright); }
.ticket.m-4 { border-left-color: var(--gold); background: linear-gradient(90deg, var(--gold-soft), var(--card) 45%); }

.mastery-chip {
  font-size: 11px; font-weight: 700; letter-spacing: 0.04em;
  padding: 3px 9px; border-radius: 999px; white-space: nowrap;
}
.mastery-chip.m-0 { background: var(--card-2); color: var(--ink-faint); }
.mastery-chip.m-1 { background: var(--bad-wash); color: var(--bad); }
.mastery-chip.m-2 { background: var(--warn-wash); color: var(--warn); }
.mastery-chip.m-3 { background: var(--blue-wash); color: var(--blue-bright); }
.mastery-chip.m-4 { background: var(--gold-soft); color: var(--gold-ink); }

/* ---------- dashboard ---------- */
.dash-grid { display: grid; grid-template-columns: 340px 1fr; gap: 16px; align-items: start; }
@media (max-width: 860px) { .dash-grid { grid-template-columns: 1fr; } }

.readiness-card { text-align: center; }
.readiness-ring { margin: 6px auto 2px; width: 168px; height: 168px; position: relative; }
.readiness-ring svg { width: 100%; height: 100%; }
.readiness-num {
  position: absolute; inset: 0; display: grid; place-items: center;
}
.readiness-num .big { font-family: var(--font-display); font-size: 40px; font-weight: 700; color: var(--ink); line-height: 1; }
.readiness-num .lbl { font-size: 11.5px; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-faint); margin-top: 4px; }

.next-activity {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: linear-gradient(135deg, var(--gold-soft), var(--card) 70%);
  padding: 14px 16px; text-align: left; margin-top: 14px;
}
.next-activity .na-label { font-size: 11.5px; font-weight: 800; letter-spacing: 0.08em; text-transform: uppercase; color: var(--gold-ink); margin-bottom: 4px;}
.next-activity .na-title { font-weight: 700; font-size: 15.5px; margin-bottom: 2px; }
.next-activity .na-why { font-size: 13px; color: var(--ink-soft); margin-bottom: 10px; }

.stat-row { display: flex; gap: 10px; margin-top: 14px; }
.stat-box {
  flex: 1; background: var(--card-2); border-radius: var(--r-md); padding: 10px 8px;
}
.stat-box .v { font-family: var(--font-display); font-size: 21px; font-weight: 700; color: var(--blue); }
:root[data-theme="dark"] .stat-box .v { color: var(--blue); }
.stat-box .k { font-size: 11px; color: var(--ink-faint); font-weight: 600; letter-spacing: 0.03em; }

.topic-group { margin-bottom: 18px; }
.topic-head {
  display: flex; align-items: baseline; gap: 10px; margin-bottom: 8px;
}
.topic-head h3 { font-size: 16px; color: var(--ink); }
.topic-head .t-count { font-size: 12.5px; color: var(--ink-faint); }
.topic-head .offquiz {
  font-size: 10.5px; font-weight: 700; letter-spacing: 0.05em; text-transform: uppercase;
  color: var(--ink-faint); border: 1px solid var(--line-strong); padding: 1.5px 7px; border-radius: 999px;
}
.ticket-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
@media (max-width: 640px) { .ticket-grid { grid-template-columns: 1fr; } }

/* step-function sparkline (CDF-style progress) */
.spark { color: var(--blue-bright); }
.spark .axis { stroke: var(--line-strong); }

/* ---------- learn view ---------- */
.learn-layout { display: grid; grid-template-columns: 290px 1fr; gap: 18px; align-items: start; }
@media (max-width: 900px) { .learn-layout { grid-template-columns: 1fr; } }
.learn-nav { position: sticky; top: 70px; max-height: calc(100vh - 90px); overflow: auto; padding-right: 4px;}
@media (max-width: 900px) { .learn-nav { position: static; max-height: none; } }
.learn-nav .ln-topic { margin-bottom: 4px; }
.learn-nav .ln-topic-head {
  width: 100%; text-align: left; font-weight: 700; font-size: 13.5px; padding: 7px 10px;
  color: var(--ink-soft); border-radius: var(--r-sm); display: flex; align-items: center; gap: 8px;
}
.learn-nav .ln-topic-head:hover { background: var(--card-2); }
.learn-nav .ln-skill {
  width: 100%; text-align: left; padding: 6px 10px 6px 26px; font-size: 13.5px; border-radius: var(--r-sm);
  color: var(--ink-soft); display: flex; align-items: center; gap: 8px;
}
.learn-nav .ln-skill:hover { background: var(--card-2); }
.learn-nav .ln-skill[aria-current="true"] { background: var(--blue-wash); color: var(--blue); font-weight: 700; }
.ln-dot { width: 8px; height: 8px; border-radius: 50%; flex: none; }
.ln-dot.m-0 { background: var(--line-strong); }
.ln-dot.m-1 { background: var(--bad); }
.ln-dot.m-2 { background: var(--warn); }
.ln-dot.m-3 { background: var(--blue-bright); }
.ln-dot.m-4 { background: var(--gold); }

.learn-article { min-width: 0; }
.learn-article .card { padding: 26px 30px; }
@media (max-width: 640px) { .learn-article .card { padding: 20px 16px; } }
.learn-article h2 { font-size: 23px; margin-bottom: 2px; }
.learn-article .skill-sub { color: var(--ink-soft); font-size: 14px; margin-bottom: 18px; }

.lsection { margin: 22px 0; }
.lsection > h3 {
  font-family: var(--font-ui); font-size: 12px; font-weight: 800; letter-spacing: 0.09em;
  text-transform: uppercase; color: var(--blue-bright); margin-bottom: 8px;
  display: flex; align-items: center; gap: 8px;
}
.lsection > h3::after { content: ""; flex: 1; height: 1px; background: var(--line); }
.lsection p { margin: 8px 0; max-width: 72ch; }
.lsection ul, .lsection ol { padding-left: 24px; margin: 8px 0; max-width: 70ch;}
.lsection li { margin: 5px 0; }

/* highlighted formula — the gold highlighter */
.formula {
  background: var(--gold-soft);
  border-left: 3px solid var(--gold);
  border-radius: var(--r-sm);
  padding: 10px 16px; margin: 10px 0;
  font-size: 16.5px;
  overflow-x: auto;
}

/* steps use real numbers because solving is sequential */
.steps { counter-reset: step; list-style: none; padding-left: 0 !important; }
.steps > li {
  counter-increment: step; position: relative; padding-left: 40px; margin: 12px 0 !important;
}
.steps > li::before {
  content: counter(step);
  position: absolute; left: 0; top: 0;
  width: 26px; height: 26px; border-radius: 50%;
  background: var(--blue-wash); color: var(--blue);
  font-weight: 800; font-size: 13px;
  display: grid; place-items: center;
  font-family: var(--font-ui);
}

.callout {
  border-radius: var(--r-md); padding: 12px 16px; margin: 10px 0; font-size: 14.5px;
  border: 1px solid var(--line);
  background: var(--card-2);
}
.callout.warn { background: var(--warn-wash); border-color: color-mix(in srgb, var(--warn) 30%, transparent); }
.callout.good { background: var(--good-wash); border-color: color-mix(in srgb, var(--good) 30%, transparent); }
.callout .co-title { font-weight: 800; font-size: 12px; letter-spacing: 0.06em; text-transform: uppercase; margin-bottom: 4px; }
.callout.warn .co-title { color: var(--warn); }
.callout.good .co-title { color: var(--good); }

.rcode {
  display: block; background: #0f1c2a; color: #dce8f5;
  border-radius: var(--r-md); padding: 12px 16px; margin: 10px 0;
  font-size: 13.5px; line-height: 1.6; overflow-x: auto; white-space: pre;
}
:root[data-theme="dark"] .rcode { background: #0a1420; border: 1px solid var(--line); }
code:not(.rcode) {
  background: var(--card-2); border: 1px solid var(--line);
  padding: 1px 6px; border-radius: 5px; font-size: 0.88em;
}
.rcode code { background: none; border: none; padding: 0; font-size: inherit; }

/* ---------- math rendering ---------- */
.math { font-family: var(--font-display); font-style: italic; white-space: nowrap; }
.math .up { font-style: normal; }
.mfrac {
  display: inline-flex; flex-direction: column; align-items: center;
  vertical-align: middle; margin: 0 3px; line-height: 1.15; font-size: 0.92em;
}
.mfrac .num { padding: 0 4px; border-bottom: 1.3px solid currentColor; }
.mfrac .den { padding: 0 4px; }
.mchoose {
  display: inline-flex; align-items: center; vertical-align: middle; margin: 0 2px;
}
.mchoose .paren { font-size: 1.9em; font-weight: 300; line-height: 0.9; font-style: normal; }
.mchoose .stack { display: inline-flex; flex-direction: column; align-items: center; line-height: 1.1; font-size: 0.85em; padding: 0 2px;}
.msqrt { display: inline-flex; align-items: stretch; vertical-align: middle; margin: 0 2px;}
.msqrt .rad { font-style: normal; font-size: 1.1em; line-height: 1.2;}
.msqrt .body { border-top: 1.3px solid currentColor; padding: 0 3px; }
sup, sub { line-height: 0; }

/* ---------- practice & quiz ---------- */
.practice-shell { max-width: 760px; margin: 0 auto; }
.practice-head { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; flex-wrap: wrap;}
.practice-head .ph-skill { font-weight: 700; font-size: 15px; }
.practice-head .spacer { flex: 1; }

.qprompt { font-size: 16.5px; margin-bottom: 16px; max-width: 70ch; }
.qprompt .rcode { font-size: 14px; }

.choices { display: flex; flex-direction: column; gap: 8px; }
.choice {
  display: flex; align-items: flex-start; gap: 12px; width: 100%;
  text-align: left; padding: 12px 16px;
  border: 1.5px solid var(--line); border-radius: var(--r-md);
  background: var(--card); font-size: 15.5px;
  transition: border-color 0.1s ease, background 0.1s ease;
}
.choice:hover { border-color: var(--blue-bright); background: var(--blue-wash); }
.choice .c-key {
  flex: none; width: 26px; height: 26px; border-radius: 50%;
  border: 1.5px solid var(--line-strong); color: var(--ink-faint);
  font-weight: 700; font-size: 13px; display: grid; place-items: center; margin-top: 1px;
  font-family: var(--font-ui);
}
.choice[aria-checked="true"] { border-color: var(--blue-bright); background: var(--blue-wash); }
.choice[aria-checked="true"] .c-key { background: var(--blue-bright); border-color: var(--blue-bright); color: #fff; }
.choice.reveal-correct { border-color: var(--good); background: var(--good-wash); }
.choice.reveal-correct .c-key { background: var(--good); border-color: var(--good); color: #fff; }
.choice.reveal-wrong { border-color: var(--bad); background: var(--bad-wash); }
.choice.reveal-wrong .c-key { background: var(--bad); border-color: var(--bad); color: #fff; }
.choice[disabled] { cursor: default; }
.choice[disabled]:hover { border-color: var(--line); background: var(--card); }
.choice.reveal-correct[disabled]:hover { border-color: var(--good); background: var(--good-wash); }
.choice.reveal-wrong[disabled]:hover { border-color: var(--bad); background: var(--bad-wash); }

.answer-input-row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.answer-input {
  flex: 1; min-width: 220px;
  padding: 10px 14px; border-radius: var(--r-md);
  border: 1.5px solid var(--line-strong); background: var(--card);
  font-family: var(--font-mono); font-size: 15px;
}
.answer-input:focus-visible { outline-offset: 0; }
.input-hint { font-size: 12.5px; color: var(--ink-faint); margin-top: 6px; }

textarea.answer-input { min-height: 74px; width: 100%; resize: vertical; line-height: 1.5;}

.feedback { border-radius: var(--r-md); padding: 14px 18px; margin-top: 16px; }
.feedback.ok { background: var(--good-wash); border: 1px solid color-mix(in srgb, var(--good) 35%, transparent); }
.feedback.no { background: var(--bad-wash); border: 1px solid color-mix(in srgb, var(--bad) 35%, transparent); }
.feedback .fb-verdict { font-weight: 800; font-size: 15px; margin-bottom: 6px; display: flex; align-items: center; gap: 8px;}
.feedback.ok .fb-verdict { color: var(--good); }
.feedback.no .fb-verdict { color: var(--bad); }
.feedback .fb-body { font-size: 14.5px; }
.feedback .fb-body p { margin: 6px 0; }

.confidence-row {
  display: flex; align-items: center; gap: 8px; margin-top: 14px; flex-wrap: wrap;
}
.confidence-row .cr-label { font-size: 13.5px; color: var(--ink-soft); font-weight: 600; }
.conf-btn {
  padding: 6px 14px; border-radius: 999px; border: 1.5px solid var(--line-strong);
  font-size: 13.5px; font-weight: 600; color: var(--ink-soft);
}
.conf-btn:hover { border-color: var(--blue-bright); color: var(--blue-bright); }
.conf-btn[aria-pressed="true"] { background: var(--blue); border-color: var(--blue); color: #fff; }

/* ---------- quiz simulator ---------- */
.quiz-setup { max-width: 620px; margin: 0 auto; }
.quiz-shell { max-width: 820px; margin: 0 auto; }
.quiz-topbar {
  display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
  padding: 10px 16px; margin-bottom: 16px;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--r-md);
  position: sticky; top: 62px; z-index: 30;
}
.quiz-timer { font-family: var(--font-mono); font-weight: 700; font-size: 16px; color: var(--blue); }
.quiz-timer.low { color: var(--bad); }
.quiz-progress-label { font-size: 13px; color: var(--ink-soft); }

.qnav { display: flex; gap: 5px; flex-wrap: wrap; }
@media (max-width: 720px) {
  /* on phones the 32 jump dots become one scrollable strip */
  .qnav {
    flex-wrap: nowrap; overflow-x: auto; width: 100%;
    padding-bottom: 4px; -webkit-overflow-scrolling: touch;
  }
  .qnav-dot { flex: none; }
  .quiz-topbar { top: 56px; }
}
.qnav-dot {
  width: 28px; height: 28px; border-radius: var(--r-sm);
  border: 1.5px solid var(--line-strong); font-size: 12px; font-weight: 700; color: var(--ink-soft);
}
.qnav-dot:hover { border-color: var(--blue-bright); }
.qnav-dot.answered { background: var(--blue-wash); border-color: var(--blue-bright); color: var(--blue); }
.qnav-dot.current { background: var(--blue); border-color: var(--blue); color: #fff; }
.qnav-dot.flagged { box-shadow: 0 0 0 2px var(--gold); }

.quiz-section-head {
  font-family: var(--font-display); font-size: 18px; font-weight: 700; color: var(--blue);
  margin: 26px 0 10px; display: flex; align-items: baseline; gap: 10px;
}
.quiz-section-head .qs-num { color: var(--ink-faint); font-size: 14px; font-family: var(--font-ui); font-weight: 600;}

.quiz-q { margin-bottom: 14px; scroll-margin-top: 130px; }
.quiz-q .qq-head { display: flex; align-items: baseline; gap: 10px; margin-bottom: 10px;}
.quiz-q .qq-num { font-weight: 800; color: var(--blue); font-family: var(--font-ui); white-space: nowrap; }
.quiz-q .qq-flag { margin-left: auto; }
.flag-btn { font-size: 12.5px; color: var(--ink-faint); border: 1px solid var(--line); border-radius: 999px; padding: 3px 10px;}
.flag-btn[aria-pressed="true"] { background: var(--gold-soft); color: var(--gold-ink); border-color: var(--gold); }

.quiz-review-banner {
  background: var(--blue-wash); border: 1px solid var(--blue-bright);
  color: var(--blue); border-radius: var(--r-md);
  padding: 12px 18px; margin-bottom: 16px; font-weight: 600; font-size: 14.5px;
}

.result-hero { text-align: center; padding: 30px 20px; }
.result-hero .score-big {
  font-family: var(--font-display); font-size: 54px; font-weight: 700; color: var(--blue); line-height: 1.05;
}
.result-hero .score-sub { color: var(--ink-soft); margin-top: 4px; }

.result-item { border-left: 4px solid var(--line-strong); }
.result-item.ok { border-left-color: var(--good); }
.result-item.no { border-left-color: var(--bad); }
.result-item .ri-head { display: flex; align-items: center; gap: 10px; flex-wrap: wrap;}
.result-item .ri-verdict { font-weight: 800; font-size: 13px; }
.result-item.ok .ri-verdict { color: var(--good); }
.result-item.no .ri-verdict { color: var(--bad); }
.result-item .ri-link { margin-left: auto; }

.given-answer { font-family: var(--font-mono); font-size: 13.5px; background: var(--card-2); border-radius: 6px; padding: 2px 8px; }

/* figure (CDF plots etc.) */
.qfigure {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--r-md);
  padding: 12px; margin: 12px 0; max-width: 480px;
}
.qfigure svg { width: 100%; height: auto; }
.qfigure .fig-caption { text-align: center; font-size: 12.5px; color: var(--ink-faint); margin-top: 4px; }
.figline { stroke: var(--blue-bright); stroke-width: 2.5; fill: none; }
.figaxis { stroke: var(--ink-faint); stroke-width: 1.2; }
.figgrid { stroke: var(--line); stroke-width: 1; stroke-dasharray: 3 4; }
.figdot { fill: var(--blue-bright); }
.figdot-open { fill: var(--card); stroke: var(--blue-bright); stroke-width: 2; }
.figtext { fill: var(--ink-soft); font-size: 12px; font-family: var(--font-ui); }

/* ---------- misc ---------- */
.pill-row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.divider { height: 1px; background: var(--line); margin: 18px 0; border: none; }
.muted { color: var(--ink-faint); font-size: 13px; }
.small { font-size: 13px; }
.mt-8 { margin-top: 8px; } .mt-16 { margin-top: 16px; } .mt-24 { margin-top: 24px; }
.row { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.row .spacer { flex: 1; }
.hidden { display: none !important; }

.empty-state { text-align: center; padding: 40px 20px; color: var(--ink-soft); }
.empty-state .es-icon { font-size: 34px; margin-bottom: 8px; }

/* toast */
.toast {
  position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%);
  background: var(--ink); color: var(--paper); padding: 10px 20px; border-radius: 999px;
  font-size: 14px; font-weight: 600; box-shadow: var(--shadow-2); z-index: 200;
  animation: toast-in 0.18s ease;
}
@keyframes toast-in { from { opacity: 0; transform: translateX(-50%) translateY(8px); } }

/* correct tick pop */
@keyframes tickpop { 0% { transform: scale(0.6); } 60% { transform: scale(1.15); } 100% { transform: scale(1); } }
.feedback .fb-verdict .tick { display: inline-block; animation: tickpop 0.25s ease; }

/* print-friendly quiz results */
@media print {
  .topbar, .appfoot, .quiz-topbar, .btn { display: none !important; }
}