/* Exam room: computer-delivered test layout. Loaded after base.css. */
html, body { height: 100%; }
body.exam-body { background: var(--surface); }
.exam { display: flex; flex-direction: column; height: 100vh; height: 100dvh; }

.exam-bar {
  display: flex; align-items: center; justify-content: space-between; gap: 10px;
  padding: 8px var(--gutter); background: var(--primary); color: var(--on-primary); flex: none;
}
.exam-bar .brand { font-weight: 800; color: inherit; text-decoration: none; }
.exam-bar .candidate { opacity: .85; font-size: .9rem; margin-left: 10px; }
.exam-bar-left, .exam-bar-right { display: flex; align-items: center; gap: 10px; min-width: 0; }
.exam-bar .btn { background: var(--surface); color: var(--primary); border-color: var(--surface); }
.exam-bar .btn-bar-ghost { background: transparent; color: var(--on-primary); border-color: rgba(255, 255, 255, .6); }
.exam-bar .badge { margin-left: 8px; }
.timer.untimed strong { font-size: .95rem; font-weight: 600; }
.timer { display: inline-flex; align-items: center; gap: 6px; }
.timer { font-variant-numeric: tabular-nums; white-space: nowrap; }
.timer strong { font-size: 1.15rem; }
.timer.warn strong { color: #ffd27a; }
.save-state { font-size: .8rem; opacity: .85; white-space: nowrap; }

.listen-bars { flex: none; }
.listen-bar {
  display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
  padding: 10px var(--gutter); background: var(--surface-2); border-bottom: 1px solid var(--border);
}
.listen-bar .volume { display: flex; align-items: center; gap: 8px; font-weight: 500; }
.demo-note { font-size: .85rem; color: var(--muted); }

.exam-main { flex: 1; min-height: 0; display: flex; overflow: hidden; }
.pane { overflow-y: auto; padding: 20px var(--gutter) 32px; }
.pane-questions { flex: 1; }
.exam-main.split .pane-passage { flex: 1; border-right: 1px solid var(--border); }
.mobile-tabs { display: none; }

.section-title { font-size: 1.2rem; }
.section-instructions { background: var(--surface-2); padding: 10px 12px; border-radius: var(--radius-small); }

/* Navigator */
.navigator {
  flex: none; display: flex; align-items: center; gap: 10px;
  padding: 8px var(--gutter); border-top: 1px solid var(--border); background: var(--surface-2); overflow-x: auto;
}
.nav-part { display: flex; align-items: center; gap: 8px; padding-right: 10px; border-right: 1px solid var(--border); }
.nav-part-label { font-weight: 700; font-size: .85rem; white-space: nowrap; }
.nav-part:not(.active) .nav-part-label { color: var(--muted); }
.nav-nums { display: flex; gap: 4px; }
.nav-num {
  position: relative; min-width: 32px; height: 32px; border: 1px solid var(--border); border-radius: var(--radius-small);
  background: var(--surface); font: inherit; font-size: .85rem; cursor: pointer;
}
.nav-num.answered { background: var(--primary); border-color: var(--primary); color: var(--on-primary); }
.nav-num.current { outline: 2px solid var(--focus); outline-offset: 1px; }
.nav-num.flagged::after {
  content: ""; position: absolute; top: -4px; right: -4px; width: 10px; height: 10px;
  border-radius: 50%; background: var(--accent); border: 2px solid var(--surface-2);
}
.nav-arrows { display: flex; gap: 6px; margin-left: auto; }

/* Intro, dialogs, overlays */
.intro { max-width: 640px; margin: 32px auto; padding: 0 var(--gutter); }
.intro ul { padding-left: 1.2em; }
.intro li { margin-bottom: .4em; }
.overlay {
  position: fixed; inset: 0; z-index: 50; display: grid; place-items: center; padding: var(--gutter);
  background: rgba(16, 24, 40, .55);
}
.overlay-solid { background: var(--surface-2); }
.dialog { width: 100%; max-width: 440px; }
.dialog-actions { display: flex; gap: 10px; justify-content: flex-end; flex-wrap: wrap; margin-top: 16px; }

@media (max-width: 860px) {
  .exam-bar .candidate, .save-state, .exam-bar .btn-label { display: none; }
  .exam-main.split { flex-direction: column; }
  .mobile-tabs {
    display: grid; grid-template-columns: 1fr 1fr; flex: none;
    border-bottom: 1px solid var(--border); background: var(--surface);
  }
  .mobile-tabs button {
    min-height: 44px; border: 0; background: none; font: inherit; font-weight: 600; color: var(--muted);
    border-bottom: 3px solid transparent;
  }
  .mobile-tabs button[aria-selected="true"] { color: var(--primary); border-bottom-color: var(--primary); }
  .exam-main.split .pane { display: none; flex: 1; border: 0; }
  .exam-main.split .pane.active { display: block; }
  .question { grid-template-columns: 38px 1fr; }
}

.exam-alert { margin: 0; border-radius: 0; }

/* Maths (KaTeX) */
.math-display { display: block; overflow-x: auto; margin: .5em 0; }
.tex-pending { font-family: inherit; color: var(--muted); }

/* CBT layout: one question per screen + numbered panel */
.cbt-body { flex: 1; min-height: 0; display: flex; position: relative; overflow: hidden; }
.cbt-main { flex: 1; min-width: 0; display: flex; flex-direction: column; overflow-y: auto; }
.cbt-question { flex: 1; width: 100%; max-width: 820px; margin: 0 auto; padding: 24px var(--gutter); }
.cbt-q-head { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 12px; }
.cbt-q-head h1 { font-size: 1.1rem; margin: 0; }
.cbt-q-head .card-tools { margin-left: auto; }
.cbt-q-head, .cbt-question .notes-toolbar { position: relative; z-index: 3; }
.cbt-question { position: relative; }
.cbt-instructions { color: var(--muted); font-size: .92rem; }
.cbt-prompt { font-size: 1.08rem; white-space: pre-line; margin-bottom: 18px; }
.cbt-image { display: block; max-height: 320px; margin: 0 0 16px; }
.cbt .options { gap: 10px; }
.cbt .option { padding: 12px 14px; }
.clear-answer { margin-top: 10px; }
.cbt-actions {
  position: sticky; bottom: 0; display: grid; grid-template-columns: 1fr auto 1fr; gap: 10px;
  padding: 10px var(--gutter); background: var(--surface); border-top: 1px solid var(--border);
}
.cbt-actions > :first-child { justify-self: start; }
.cbt-actions > :last-child { justify-self: end; }
.btn-unsure { background: var(--surface); color: var(--warn); border-color: var(--warn); }
.btn-unsure:hover { background: #fff6e5; }
.btn-unsure.on { background: #f5b83d; color: #3d2a00; border-color: #f5b83d; }

.cbt-panel { width: 300px; flex: none; overflow-y: auto; border-left: 1px solid var(--border); background: var(--surface-2); }
.cbt-panel-inner { padding: 16px; }
.cbt-panel-section h2 { font-size: .95rem; margin: 8px 0; }
.cbt-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 6px; margin-bottom: 12px; }
.cbt-num {
  display: inline-grid; place-items: center; min-width: 32px; height: 36px;
  border: 1px solid var(--border); border-radius: var(--radius-small);
  background: var(--surface); font: inherit; font-size: .9rem; cursor: pointer;
}
.cbt-num.answered { background: var(--primary); border-color: var(--primary); color: var(--on-primary); }
.cbt-num.unsure { background: #f5b83d; border-color: #f5b83d; color: #3d2a00; }
.cbt-num.current { outline: 3px solid var(--focus); outline-offset: 1px; }
.cbt-legend { list-style: none; padding: 0; margin: 8px 0 0; font-size: .85rem; display: grid; gap: 6px; }
.cbt-legend li { display: flex; align-items: center; gap: 8px; }
.cbt-legend .cbt-num { min-width: 18px; width: 18px; height: 18px; cursor: default; }
.cbt-panel-toggle { display: none; }

@media (max-width: 860px) {
  .cbt-panel {
    position: absolute; inset: 0 0 0 auto; width: min(320px, 90vw); z-index: 20;
    transform: translateX(100%); transition: transform .2s ease; box-shadow: var(--shadow);
  }
  .cbt-panel.open { transform: none; }
  .cbt-panel-toggle { display: inline-grid; position: absolute; right: var(--gutter); top: 14px; z-index: 21; }
  .cbt-question { padding-top: 16px; }
  .cbt-q-head { padding-right: 56px; flex-wrap: wrap; }
  .cbt-actions { grid-template-columns: auto 1fr auto; gap: 8px; }
  .cbt-actions .btn { padding: .5em .8em; font-size: .9rem; white-space: nowrap; }
  .cbt-actions .btn-unsure { width: 100%; }
  .cbt-actions .btn-label { display: none; }
  .cbt-panel-inner { padding-top: 64px; }
}