:root {
  --bg: #eef1f5;
  --surface: #ffffff;
  --ink: #1a2230;
  --ink-soft: #566074;
  --line: #d8dee8;
  --brand: #1f5fa8;
  --brand-dark: #17497f;
  --accent: #f0f4fa;
  --correct: #1a8a4a;
  --correct-bg: #e5f5eb;
  --wrong: #c62f37;
  --wrong-bg: #fbe9ea;
  --flag: #d98a00;
  --shadow: 0 1px 3px rgba(16,30,54,.08), 0 6px 20px rgba(16,30,54,.06);
  --radius: 10px;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.5;
}
.hidden { display: none !important; }

/* ---------- generic ---------- */
.screen { min-height: 100vh; }
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.btn {
  font: inherit;
  font-weight: 600;
  border: 1px solid transparent;
  border-radius: 8px;
  padding: .55rem 1rem;
  cursor: pointer;
  background: #e6eaf1;
  color: var(--ink);
  transition: background .12s, border-color .12s, transform .04s;
}
.btn:hover { background: #dce2ec; }
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); }
.btn-ghost { background: transparent; border-color: var(--line); }
.btn-ghost:hover { background: var(--accent); }
.btn-ghost:disabled { opacity: .4; cursor: default; background: transparent; }
.btn-lg { padding: .8rem 1.4rem; font-size: 1.05rem; width: 100%; }
.btn-flag { background: transparent; border-color: var(--line); color: var(--ink-soft); }
.btn-flag.active { background: #fdf2dd; border-color: var(--flag); color: var(--flag); }

/* ---------- start screen ---------- */
#start-screen {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  padding: 2rem; gap: 1rem;
}
.start-card { max-width: 560px; width: 100%; padding: 2.2rem; }
.start-card h1 { margin: 0 0 .25rem; font-size: 1.9rem; }
.subtitle { margin: 0 0 1.6rem; color: var(--ink-soft); }
.mode-group { display: grid; gap: .75rem; margin-bottom: 1.4rem; }
.mode-option {
  display: flex; gap: .8rem; align-items: flex-start;
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1rem; cursor: pointer; transition: border-color .12s, background .12s;
}
.mode-option:hover { background: var(--accent); }
.mode-option input { margin-top: .3rem; accent-color: var(--brand); }
.mode-option:has(input:checked) { border-color: var(--brand); background: var(--accent); box-shadow: inset 0 0 0 1px var(--brand); }
.mode-body { display: flex; flex-direction: column; }
.mode-body strong { font-size: 1.05rem; }
.mode-body span { color: var(--ink-soft); font-size: .9rem; }
.timer-config { display: flex; align-items: center; gap: .75rem; margin-bottom: 1.4rem; }
.timer-config label { color: var(--ink-soft); font-weight: 600; }
.timer-config select {
  font: inherit; padding: .5rem .7rem; border: 1px solid var(--line);
  border-radius: 8px; background: #fff; color: var(--ink); flex: 1;
}
.footnote { color: var(--ink-soft); font-size: .8rem; }
.resume-banner {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  background: var(--accent); border: 1px solid var(--brand);
  border-radius: var(--radius); padding: 1rem; margin-bottom: 1.4rem; flex-wrap: wrap;
}
.resume-banner > div { display: flex; gap: .5rem; }

/* ---------- exam screen ---------- */
.topbar {
  position: sticky; top: 0; z-index: 5;
  display: flex; align-items: center; justify-content: space-between;
  background: var(--surface); border-bottom: 1px solid var(--line);
  padding: .7rem 1.2rem; box-shadow: var(--shadow);
}
.topbar-left, .topbar-right { display: flex; align-items: center; gap: 1rem; }
.badge {
  background: var(--brand); color: #fff; font-size: .75rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: .04em; padding: .25rem .6rem; border-radius: 999px;
}
#progress-text { color: var(--ink-soft); font-size: .9rem; }
.timer { font-variant-numeric: tabular-nums; font-weight: 700; font-size: 1.15rem; }
.timer.warn { color: var(--flag); }
.timer.danger { color: var(--wrong); }

.exam-body {
  display: grid; grid-template-columns: 1fr 260px; gap: 1.4rem;
  max-width: 1180px; margin: 0 auto; padding: 1.6rem 1.2rem;
}
.question-pane { padding: 1.8rem; }
.q-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 1rem; }
.q-number { font-weight: 700; color: var(--brand); font-size: 1.05rem; }
.q-stem { font-size: 1.2rem; margin: 0 0 1.4rem; }
.q-options { display: grid; gap: .7rem; }
.opt {
  display: flex; gap: .8rem; align-items: flex-start;
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: .9rem 1rem; cursor: pointer; transition: border-color .12s, background .12s;
}
.opt:hover { background: var(--accent); }
.opt.selected { border-color: var(--brand); background: var(--accent); box-shadow: inset 0 0 0 1px var(--brand); }
.opt .letter {
  flex: 0 0 auto; width: 1.6rem; height: 1.6rem; border-radius: 50%;
  display: grid; place-items: center; font-weight: 700; font-size: .85rem;
  background: #e6eaf1; color: var(--ink-soft);
}
.opt.selected .letter { background: var(--brand); color: #fff; }
.opt.correct { border-color: var(--correct); background: var(--correct-bg); }
.opt.correct .letter { background: var(--correct); color: #fff; }
.opt.incorrect { border-color: var(--wrong); background: var(--wrong-bg); }
.opt.incorrect .letter { background: var(--wrong); color: #fff; }
.opt.disabled { cursor: default; }
.opt.disabled:hover { background: inherit; }

.feedback { margin-top: 1.2rem; padding: .9rem 1rem; border-radius: var(--radius); font-weight: 600; }
.feedback.right { background: var(--correct-bg); color: var(--correct); }
.feedback.wrong { background: var(--wrong-bg); color: var(--wrong); }

.q-nav { display: flex; justify-content: space-between; margin-top: 2rem; }

/* ---------- grid pane ---------- */
.grid-pane { position: sticky; top: 76px; align-self: start; }
.grid-legend { display: grid; grid-template-columns: 1fr 1fr; gap: .35rem; font-size: .8rem; color: var(--ink-soft); margin-bottom: .8rem; }
.grid-legend span { display: flex; align-items: center; gap: .4rem; }
.sw { width: .9rem; height: .9rem; border-radius: 4px; border: 1px solid var(--line); display: inline-block; }
.sw.answered { background: var(--brand); border-color: var(--brand); }
.sw.flagged { background: #fdf2dd; border-color: var(--flag); }
.sw.current { background: #fff; border: 2px solid var(--ink); }
.sw.unanswered { background: #fff; }
.nav-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: .3rem; max-height: 62vh; overflow-y: auto; padding-right: 4px; }
.cell {
  aspect-ratio: 1; border: 1px solid var(--line); border-radius: 6px;
  background: #fff; font-size: .8rem; font-weight: 600; color: var(--ink-soft);
  cursor: pointer; display: grid; place-items: center; position: relative;
}
.cell:hover { border-color: var(--brand); }
.cell.answered { background: var(--brand); border-color: var(--brand); color: #fff; }
.cell.flagged { box-shadow: inset 0 0 0 2px var(--flag); }
.cell.current { outline: 2px solid var(--ink); outline-offset: 1px; }
.cell.correct { background: var(--correct); border-color: var(--correct); color: #fff; }
.cell.incorrect { background: var(--wrong); border-color: var(--wrong); color: #fff; }

/* ---------- results ---------- */
.results-wrap { max-width: 820px; margin: 0 auto; padding: 2rem 1.2rem; }
.score-card { padding: 2.2rem; text-align: center; margin-bottom: 1.6rem; }
.score-card h1 { margin: 0 0 1.2rem; }
.score-ring {
  width: 160px; height: 160px; margin: 0 auto 1rem; border-radius: 50%;
  display: grid; place-items: center;
  background: conic-gradient(var(--brand) var(--pct, 0%), #e6eaf1 0);
}
.score-ring span { width: 120px; height: 120px; background: #fff; border-radius: 50%; display: grid; place-items: center; font-size: 2rem; font-weight: 800; }
.score-line { color: var(--ink-soft); font-size: 1.05rem; margin: 0 0 1.4rem; }
.results-actions { display: flex; gap: .6rem; justify-content: center; flex-wrap: wrap; }

.review-list { display: grid; gap: 1rem; }
.review-item { padding: 1.4rem 1.6rem; }
.review-item .q-number { font-size: .9rem; }
.review-item.correct-item { border-left: 4px solid var(--correct); }
.review-item.incorrect-item { border-left: 4px solid var(--wrong); }
.review-stem { font-weight: 600; margin: .4rem 0 .9rem; }
.review-opts { display: grid; gap: .4rem; }
.review-opt { display: flex; gap: .6rem; padding: .5rem .7rem; border-radius: 8px; font-size: .95rem; }
.review-opt .letter { flex: 0 0 auto; width: 1.4rem; height: 1.4rem; border-radius: 50%; display: grid; place-items: center; font-weight: 700; font-size: .75rem; background: #e6eaf1; color: var(--ink-soft); }
.review-opt.correct { background: var(--correct-bg); }
.review-opt.correct .letter { background: var(--correct); color: #fff; }
.review-opt.chosen-wrong { background: var(--wrong-bg); }
.review-opt.chosen-wrong .letter { background: var(--wrong); color: #fff; }
.review-tag { font-size: .8rem; font-weight: 700; margin-left: .5rem; }
.review-tag.ok { color: var(--correct); }
.review-tag.bad { color: var(--wrong); }

@media (max-width: 820px) {
  .exam-body { grid-template-columns: 1fr; }
  .grid-pane { position: static; order: -1; }
  .nav-grid { max-height: none; }
}

/* =========================================================
   PEARSON VUE "drab" skin  (body.skin-pearson)
   Grounded on Pearson VUE's own tutorial: title bar with
   exam name + Time Remaining + item progress, a tool bar
   (Flag / Comment / Highlight / Strikethrough), one question
   at a time, radio-circle options, and an end-of-block Item
   Review screen. Header hue is a placeholder pending live
   confirmation.
   ========================================================= */
#pv-header { display: none; }
.pv-hidden { visibility: hidden; }

body.skin-pearson {
  background: #e9e9e9;
  color: #1a1a1a;
  font-family: Arial, Helvetica, "Liberation Sans", sans-serif;
}
body.skin-pearson .topbar { display: none; }
body.skin-pearson #pv-header { display: block; }

/* title bar */
.pv-header { border-bottom: 1px solid #7d7d7d; }
.pv-titlebar {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; background: #1f4e88; color: #fff;      /* PLACEHOLDER hue */
  padding: .45rem .9rem; font-size: .9rem;
}
.pv-examname { font-weight: 700; }
.pv-status { display: flex; align-items: center; gap: 1.6rem; }
.pv-block { display: inline-flex; align-items: center; gap: .4rem; }
.pv-label { font-size: .8rem; opacity: .92; }
.pv-timerval, .pv-progval { font-weight: 700; font-variant-numeric: tabular-nums; }
.pv-icon {
  background: transparent; border: 1px solid rgba(255,255,255,.5); color: #fff;
  border-radius: 2px; cursor: pointer; font-size: .85rem; line-height: 1; padding: .1rem .3rem;
}
.pv-icon:hover { background: rgba(255,255,255,.15); }

/* tool bar */
.pv-toolbar {
  display: flex; align-items: center; gap: .4rem; flex-wrap: wrap;
  background: #d7d7d7; border-top: 1px solid #b8b8b8; padding: .35rem .7rem;
}
.pv-tool {
  font: inherit; font-size: .82rem; background: #f4f4f4; color: #1a1a1a;
  border: 1px solid #8a8a8a; border-radius: 2px; padding: .3rem .6rem; cursor: pointer;
}
.pv-tool:hover { background: #e8e8e8; }
.pv-tool:active { background: #dcdcdc; }
.pv-tool.active { background: #cfe0f5; border-color: #1f4e88; }
.js-flag.active .pv-flagicon { color: #b00020; }
.pv-hlcolor { font: inherit; font-size: .8rem; padding: .25rem; border: 1px solid #8a8a8a; border-radius: 2px; }

/* body: single column, boxy white panel, no side grid */
body.skin-pearson .exam-body { grid-template-columns: 1fr; max-width: 900px; padding: 1.2rem; }
body.skin-pearson .grid-pane { display: none; }
body.skin-pearson .question-pane {
  background: #fff; border: 1px solid #8a8a8a; border-radius: 0; box-shadow: none; padding: 1.4rem 1.6rem;
}
body.skin-pearson .q-header { margin-bottom: .8rem; }
body.skin-pearson .q-number { color: #1a1a1a; font-size: 1rem; }
body.skin-pearson .btn-flag { display: none; }   /* flag lives in the tool bar */
body.skin-pearson .q-stem { font-size: 1rem; line-height: 1.55; }

/* radio-circle options */
.pv-opt {
  display: flex; align-items: baseline; gap: .55rem;
  border: 0; background: none; box-shadow: none; border-radius: 0;
  padding: .35rem .4rem; cursor: pointer;
}
.pv-opt:hover { background: #eef3fb; }
.pv-radio {
  flex: 0 0 auto; width: 14px; height: 14px; border: 1px solid #555; border-radius: 50%;
  position: relative; top: 2px; background: #fff;
}
.pv-opt.selected .pv-radio::after {
  content: ""; position: absolute; inset: 3px; background: #1a1a1a; border-radius: 50%;
}
.pv-optletter { font-weight: 700; }
.mark-st { text-decoration: line-through; }

/* comment box */
.pv-commentbox { margin-top: 1rem; border: 1px solid #8a8a8a; background: #fafafa; padding: .6rem .7rem; }
.pv-commentbox label { display: block; font-size: .8rem; color: #444; margin-bottom: .3rem; }
.pv-commentbox textarea { width: 100%; font: inherit; font-size: .9rem; border: 1px solid #8a8a8a; padding: .4rem; resize: vertical; }

/* footer nav */
body.skin-pearson .q-nav { justify-content: flex-end; gap: .5rem; margin-top: 1.6rem; }
body.skin-pearson .q-nav .btn {
  background: #f4f4f4; border: 1px solid #8a8a8a; border-radius: 2px; color: #1a1a1a; font-weight: 400;
}
body.skin-pearson .q-nav .btn:hover:not(:disabled) { background: #e8e8e8; }

/* Item Review screen */
.pv-review {
  max-width: 780px; margin: 1.5rem auto; background: #fff;
  border: 1px solid #8a8a8a; padding: 1.3rem 1.5rem;
}
.pv-review h2 { margin: 0 0 .6rem; font-size: 1.2rem; }
.pv-review-help { font-size: .88rem; color: #444; margin: 0 0 1rem; }
.pv-review-actions { display: flex; gap: .5rem; flex-wrap: wrap; margin-bottom: 1rem; }
.pv-btn {
  font: inherit; font-size: .85rem; background: #f4f4f4; border: 1px solid #8a8a8a;
  border-radius: 2px; padding: .4rem .8rem; cursor: pointer;
}
.pv-btn:hover { background: #e8e8e8; }
.pv-primary { background: #1f4e88; color: #fff; border-color: #163a66; }
.pv-primary:hover { background: #163a66; }
.pv-review-tablewrap { overflow-x: auto; }
.pv-review-table { width: 100%; border-collapse: collapse; font-size: .88rem; }
.pv-review-table th, .pv-review-table td {
  border: 1px solid #cfcfcf; padding: .35rem .6rem; text-align: left;
}
.pv-review-table th { background: #eee; font-weight: 700; }
.pv-qlink { background: none; border: 0; color: #1f4e88; font: inherit; cursor: pointer; text-decoration: underline; padding: 0; }
.pv-incomplete { color: #b00020; font-weight: 600; }

/* toggle toast (both skins) */
.pv-toast {
  position: fixed; bottom: 22px; left: 50%; transform: translateX(-50%);
  background: #2b2b2b; color: #fff; padding: .5rem .9rem; border-radius: 4px;
  font-size: .85rem; letter-spacing: .01em; opacity: 0; pointer-events: none;
  transition: opacity .2s; z-index: 100;
}
.pv-toast.show { opacity: .93; }