/* KLR AI Lab — Shared Exam Theme
   Applied to all exam prep pages.
   Covers every component variant across all 6 pages.
*/

/* ── Design tokens ── */
:root {
  --bg:           #0d0f14;
  --surface:      #1a1d26;
  --card:         #1e2230;
  --border:       #252a3a;
  --accent:       #4a9eff;
  --accent-glow:  rgba(74,158,255,0.2);
  --correct:      #3dd68c;
  --wrong:        #ff4757;
  --warn:         #ffa502;
  --text:         #f5ebe0;
  --muted:        #b8a898;
  --dim:          #5a6070;
  --font-display: 'Exo 2', sans-serif;
  --font-body:    'Inter', sans-serif;
  --font-mono:    'DM Mono', monospace;
}

/* ── Reset ── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

/* ── Body + grid background ── */
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  min-height: 100vh;
  overflow-x: hidden;
}
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(74,158,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(74,158,255,0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 0;
}

/* ── Layout containers ── */
.container, #app {
  max-width: 860px;
  margin: 0 auto;
  padding: 20px;
  position: relative;
  z-index: 1;
}

/* ── Header / top nav ── */
header {
  padding: 20px 0 16px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 32px;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.top-nav-subtitle {
  font-size: 13px;
  color: var(--muted);
}
.top-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 28px;
  gap: 16px;
  flex-wrap: wrap;
}

/* ── Logo / brand ── */
.logo, .brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text);
}
.logo-badge {
  width: 38px; height: 38px;
  background: linear-gradient(135deg, var(--accent), #2a6abf);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 18px;
  box-shadow: 0 0 16px var(--accent-glow);
}
.logo-text, .brand-name {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--text);
}
.logo-text span, .brand-name span { color: var(--accent); }
.header-meta, .exam-meta {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--dim);
  text-align: right;
  line-height: 1.6;
}

/* ── Tab bar (AB900 top tabs) ── */
.tab-bar {
  display: flex;
  gap: 4px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 4px;
}
.tab-bar .tab {
  flex: 1;
  padding: 8px 16px;
  border: none;
  background: transparent;
  color: var(--muted);
  font-family: var(--font-display);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.5px;
  cursor: pointer;
  border-radius: 8px;
  transition: all 0.2s;
  text-transform: uppercase;
  white-space: nowrap;
}
.tab-bar .tab:hover { color: var(--text); background: rgba(74,158,255,0.05); }
.tab-bar .tab.active {
  background: rgba(74,158,255,0.12);
  color: var(--accent);
  box-shadow: inset 0 0 0 1px rgba(74,158,255,0.3);
}

/* Pane visibility (AB900) */
.guide, .cheat, .exam-pane { display: none; }
.guide.active, .cheat.active, .exam-pane.active { display: block; }

/* ── Progress bar ── */
.quiz-header, .quiz-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  gap: 12px;
}
.progress-wrap { flex: 1; }
.progress-info {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--dim);
  margin-bottom: 6px;
}
.progress-bar {
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), #2a6abf);
  border-radius: 2px;
  transition: width 0.4s ease;
}

/* exam.html uses .progress-wrap > div for the bar */
.progress-wrap > div:not(.progress-info):not(.progress-fill) {
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
}

/* ── Score badge / pill ── */
.score-badge, .score-pill {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 5px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
  white-space: nowrap;
}
.score-badge span { color: var(--text); }
.correct-score { color: var(--correct) !important; }

/* Control buttons */
.ctrl-group { display: flex; gap: 8px; }
.ctrl-btn {
  width: 36px; height: 36px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--muted);
  font-size: 16px;
  cursor: pointer;
  transition: all 0.15s;
  display: flex; align-items: center; justify-content: center;
}
.ctrl-btn:hover { border-color: var(--accent); color: var(--accent); }

/* ── Mode / start screen ── */
.screen-title, .start-title {
  font-family: var(--font-display);
  font-size: clamp(24px, 5vw, 42px);
  font-weight: 900;
  letter-spacing: 1px;
  line-height: 1.1;
  margin-bottom: 8px;
}
.screen-title span, .start-title span { color: var(--accent); }
.screen-sub, .start-sub {
  color: var(--muted);
  font-size: 15px;
  margin-bottom: 36px;
  font-weight: 300;
}

/* exam.html start screen */
.start-screen { text-align: center; padding: 40px 0; }
.start-icon { font-size: 48px; margin-bottom: 16px; display: block; }
.pill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 auto 32px;
  justify-content: center;
  max-width: 560px;
}
.pill {
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 6px 14px;
  border-radius: 20px;
  font-family: var(--font-mono);
  font-size: 12px;
}

/* ── Filter / topic bars ── */
.filter-bar, .filter-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 28px;
  align-items: center;
}
.filter-label {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--dim);
  margin-right: 4px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.filter-btn, .topic-btn {
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 6px 14px;
  border-radius: 20px;
  font-family: var(--font-body);
  font-size: 12px;
  cursor: pointer;
  transition: all 0.15s;
}
.filter-btn:hover, .topic-btn:hover { border-color: var(--accent); color: var(--accent); }
.filter-btn.active, .topic-btn.active {
  background: rgba(74,158,255,0.12);
  border-color: var(--accent);
  color: var(--accent);
}
.question-count-display {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--dim);
  margin-left: auto;
}

/* Count selector */
.count-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}
.count-label {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--dim);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.count-btn {
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 5px 14px;
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  cursor: pointer;
  transition: all 0.15s;
}
.count-btn:hover { border-color: var(--accent); color: var(--accent); }
.count-btn.active {
  background: rgba(74,158,255,0.12);
  border-color: var(--accent);
  color: var(--accent);
}

/* ── Mode selection cards ── */
.mode-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 32px; }
.mode-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px 24px;
  cursor: pointer;
  transition: all 0.2s;
  position: relative;
  overflow: hidden;
}
.mode-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), transparent);
  opacity: 0;
  transition: opacity 0.2s;
}
.mode-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,0.3); }
.mode-card:hover::before, .mode-card.active::before { opacity: 1; }
.mode-card.active { border-color: var(--accent); background: rgba(74,158,255,0.06); }
.mode-icon { font-size: 28px; margin-bottom: 12px; }
.mode-name { font-family: var(--font-display); font-size: 14px; font-weight: 700; letter-spacing: 0.5px; margin-bottom: 8px; }
.mode-desc { font-size: 13px; color: var(--muted); line-height: 1.5; font-weight: 300; }

/* ── Question card ── */
.question-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 32px;
  margin-bottom: 20px;
  animation: fadeIn 0.25s ease;
}
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

/* Question metadata */
.domain-tag, .q-meta {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--accent);
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.domain-tag::before, .q-meta::before {
  content: '';
  width: 4px; height: 4px;
  background: var(--accent);
  border-radius: 50%;
  flex-shrink: 0;
}
.q-topic-tag {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--dim);
  letter-spacing: 0.5px;
}
.q-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--dim);
}
.q-text, .question-text {
  font-size: 16px;
  line-height: 1.65;
  margin-bottom: 28px;
  font-weight: 400;
  color: var(--text);
}
.multi-badge, .multi-hint {
  display: inline-block;
  background: rgba(255,165,2,0.1);
  border: 1px solid rgba(255,165,2,0.3);
  color: var(--warn);
  font-family: var(--font-mono);
  font-size: 10px;
  padding: 2px 8px;
  border-radius: 4px;
  letter-spacing: 0.5px;
  margin-bottom: 14px;
}

/* ── Answer options ── */
.options-list, .choices {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.option-btn, .choice {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 18px;
  text-align: left;
  cursor: pointer;
  transition: all 0.15s;
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--text);
  display: flex;
  align-items: flex-start;
  gap: 12px;
  line-height: 1.5;
  width: 100%;
}
.option-btn:hover:not(:disabled),
.choice:hover:not(:disabled) { border-color: var(--accent); background: rgba(74,158,255,0.05); }
.option-btn.selected, .choice.selected {
  border-color: var(--accent);
  background: rgba(74,158,255,0.1);
}
.option-btn.correct-ans, .choice.correct {
  border-color: var(--correct);
  background: rgba(61,214,140,0.08);
  color: var(--correct);
}
.option-btn.wrong-ans, .choice.wrong, .choice.missed {
  border-color: var(--wrong);
  background: rgba(255,71,87,0.08);
  color: var(--wrong);
}
.option-btn:disabled, .choice:disabled { cursor: default; }

/* Option letter / marker */
.option-letter, .choice-marker, .opt-letter {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--dim);
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding-top: 1px;
}
.option-btn.correct-ans .option-letter,
.choice.correct .choice-marker,
.choice.correct .opt-letter { color: var(--correct); }
.option-btn.wrong-ans .option-letter,
.choice.wrong .choice-marker,
.choice.missed .choice-marker { color: var(--wrong); }
.option-btn.selected .option-letter,
.choice.selected .choice-marker { color: var(--accent); }
.choice-text { flex: 1; }
.option-content { display: flex; flex-direction: column; flex: 1; }

/* ── Action row & buttons ── */
.action-row {
  display: flex;
  gap: 12px;
  margin-top: 20px;
  align-items: center;
  flex-wrap: wrap;
}
.start-btn, .btn-primary, .check-btn, .btn-submit {
  background: linear-gradient(135deg, var(--accent), #2a6abf);
  color: #fff;
  border: none;
  padding: 12px 28px;
  border-radius: 10px;
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1px;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: 0 4px 20px rgba(74,158,255,0.25);
}
.start-btn { padding: 14px 40px; }
.start-btn:hover,
.btn-primary:hover,
.check-btn:hover:not(:disabled),
.btn-submit:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: 0 8px 28px rgba(74,158,255,0.4);
}
.start-btn:disabled,
.btn-primary:disabled,
.check-btn:disabled,
.btn-submit:disabled { opacity: 0.4; cursor: not-allowed; transform: none; box-shadow: none; }

.next-btn, .btn-secondary, .btn-skip {
  background: var(--card);
  color: var(--accent);
  border: 1px solid var(--accent);
  padding: 12px 28px;
  border-radius: 10px;
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1px;
  cursor: pointer;
  transition: all 0.2s;
}
.next-btn:hover, .btn-secondary:hover, .btn-skip:hover { background: rgba(74,158,255,0.1); }

/* ── Feedback banners ── */
.feedback {
  padding: 12px 20px;
  border-radius: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.5px;
  margin-top: 16px;
  animation: fadeIn 0.2s ease;
}
.feedback.pass {
  background: rgba(61,214,140,0.1);
  border: 1px solid var(--correct);
  color: var(--correct);
}
.feedback.fail {
  background: rgba(255,71,87,0.08);
  border: 1px solid var(--wrong);
  color: var(--wrong);
}

/* ── Explanation box ── */
.explanation-box {
  background: rgba(74,158,255,0.05);
  border: 1px solid rgba(74,158,255,0.2);
  border-radius: 12px;
  padding: 16px 20px;
  margin-top: 16px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
  animation: fadeIn 0.2s ease;
}
.explanation-box strong {
  color: var(--accent);
  font-size: 11px;
  font-family: var(--font-mono);
  letter-spacing: 0.5px;
  display: block;
  margin-bottom: 6px;
  text-transform: uppercase;
}
.wrong-reason {
  font-size: 12px; color: rgba(255,71,87,0.8);
  margin-top: 8px; padding-top: 8px;
  border-top: 1px solid rgba(255,71,87,0.2);
  line-height: 1.5; font-weight: 300;
}
.correct-reason {
  font-size: 12px; color: rgba(61,214,140,0.8);
  margin-top: 8px; padding-top: 8px;
  border-top: 1px solid rgba(61,214,140,0.2);
  line-height: 1.5; font-weight: 300;
}
.wrong-item { display: flex; gap: 10px; margin-bottom: 8px; align-items: flex-start; }
.wrong-item-letter { font-family: var(--font-mono); font-size: 11px; color: var(--wrong); width: 18px; flex-shrink: 0; }
.wrong-item-text { font-size: 12px; color: var(--muted); line-height: 1.5; }
.explanation-box .wrong-breakdown { margin-top: 14px; padding-top: 14px; border-top: 1px solid rgba(74,158,255,0.15); }
.explanation-box .wrong-breakdown-title { font-family: var(--font-mono); font-size: 10px; color: var(--dim); text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 10px; }

/* ── Flash card ── */
.flash-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 40px 32px;
  min-height: 280px;
  cursor: pointer;
  transition: all 0.3s;
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: center;
  animation: fadeIn 0.25s ease;
}
.flash-card:hover { border-color: var(--accent); box-shadow: 0 0 0 1px rgba(74,158,255,0.15); }
.flash-front { text-align: center; }
.flash-hint {
  font-family: var(--font-mono); font-size: 11px; color: var(--dim);
  margin-top: 20px; display: flex; align-items: center; justify-content: center; gap: 6px;
}
.flash-answer { animation: fadeIn 0.2s ease; }
.flash-answer-label {
  font-family: var(--font-mono); font-size: 10px; color: var(--correct);
  letter-spacing: 1px; text-transform: uppercase; margin-bottom: 12px;
}
.flash-answer-text { font-size: 15px; font-weight: 600; color: var(--correct); margin-bottom: 16px; line-height: 1.4; }
.flash-actions { display: flex; gap: 12px; margin-top: 24px; justify-content: center; }
.flash-got-it {
  background: rgba(61,214,140,0.1); border: 1px solid var(--correct); color: var(--correct);
  padding: 10px 24px; border-radius: 8px; font-family: var(--font-display); font-size: 12px;
  font-weight: 700; letter-spacing: 1px; cursor: pointer; transition: all 0.15s;
}
.flash-got-it:hover { background: rgba(61,214,140,0.2); }
.flash-missed {
  background: rgba(255,71,87,0.08); border: 1px solid var(--wrong); color: var(--wrong);
  padding: 10px 24px; border-radius: 8px; font-family: var(--font-display); font-size: 12px;
  font-weight: 700; letter-spacing: 1px; cursor: pointer; transition: all 0.15s;
}
.flash-missed:hover { background: rgba(255,71,87,0.15); }

/* ── Results ── */
.results-card, .results-screen {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 44px 40px;
  animation: fadeIn 0.3s ease;
}
.results-hero { text-align: center; margin-bottom: 32px; }

/* Score ring */
.score-ring, .results-score-ring {
  width: 120px; height: 120px;
  border-radius: 50%;
  background: conic-gradient(var(--accent) var(--pct, 0%), var(--border) var(--pct, 0%));
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 24px;
  position: relative;
}
.score-ring::before, .results-score-ring::before {
  content: '';
  position: absolute;
  inset: 12px;
  background: var(--card);
  border-radius: 50%;
}
.score-ring-val, .results-score-ring > span {
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 900;
  position: relative;
  z-index: 1;
  color: var(--accent);
}
.results-title {
  font-family: var(--font-display); font-size: 20px; font-weight: 900;
  margin-bottom: 8px; letter-spacing: 1px;
}
.results-sub { color: var(--muted); font-size: 14px; margin-bottom: 32px; }

/* Stats */
.stats-row, .results-stats {
  display: flex; gap: 32px; justify-content: center; margin-bottom: 32px; flex-wrap: wrap;
}
.stat { text-align: center; }
.stat-val {
  font-family: var(--font-display); font-size: 28px; font-weight: 900; display: block;
}
.stat-val.green { color: var(--correct); }
.stat-val.red   { color: var(--wrong); }
.stat-label {
  font-family: var(--font-mono); font-size: 11px; color: var(--dim);
  margin-top: 4px; text-transform: uppercase; letter-spacing: 0.5px;
}

/* Topic breakdown */
.breakdown { margin-bottom: 32px; text-align: left; }
.breakdown-title {
  font-family: var(--font-mono); font-size: 11px; color: var(--dim);
  text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 16px;
}
.topic-row { display: flex; align-items: center; gap: 12px; margin-bottom: 10px; }
.topic-row-name { font-size: 12px; color: var(--muted); min-width: 180px; }
.topic-bar { flex: 1; height: 5px; background: var(--border); border-radius: 3px; overflow: hidden; }
.topic-fill { height: 100%; border-radius: 3px; background: var(--accent); transition: width 0.6s ease; }
.topic-pct { font-family: var(--font-mono); font-size: 11px; color: var(--muted); min-width: 36px; text-align: right; }

/* Missed questions */
.missed-section { text-align: left; margin-top: 24px; }
.missed-title, .missed-section h3 {
  font-family: var(--font-mono); font-size: 11px; color: var(--dim);
  text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 16px;
}
.missed-item {
  background: var(--surface);
  border: 1px solid rgba(255,71,87,0.2);
  border-left: 3px solid var(--wrong);
  border-radius: 10px;
  padding: 14px 16px;
  margin-bottom: 10px;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.5;
}
.missed-item .correct-lbl, .missed-item strong {
  font-family: var(--font-mono); font-size: 10px; color: var(--correct);
  text-transform: uppercase; letter-spacing: 0.5px;
  display: block; margin-top: 8px;
}

/* Results buttons */
.results-btns { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* ── Modal ── */
.modal-overlay {
  position: fixed; inset: 0; background: rgba(0,0,0,0.7);
  display: flex; align-items: center; justify-content: center;
  z-index: 100; animation: fadeIn 0.15s ease;
}
.modal-box {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 16px; padding: 32px; max-width: 380px; width: 90%; text-align: center;
}
.modal-title { font-family: var(--font-display); font-size: 16px; font-weight: 700; margin-bottom: 10px; letter-spacing: 0.5px; }
.modal-text { font-size: 14px; color: var(--muted); margin-bottom: 24px; line-height: 1.5; }
.modal-btns { display: flex; gap: 10px; justify-content: center; }

/* ── AB900 study guide & cheat sheet ── */
.section-title {
  font-family: var(--font-display);
  font-size: 18px; font-weight: 700; letter-spacing: 0.5px;
  margin-bottom: 20px; color: var(--text);
}
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 24px; }
.grid-3 { display: grid; grid-template-columns: repeat(3,1fr); gap: 16px; margin-bottom: 24px; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
}
.card h3 { font-family: var(--font-display); font-size: 13px; font-weight: 700; margin-bottom: 10px; color: var(--text); }
.card p, .card li { font-size: 13px; color: var(--muted); line-height: 1.6; }
.card ul { padding-left: 16px; }
.tag {
  display: inline-block;
  padding: 2px 8px; border-radius: 4px;
  font-family: var(--font-mono); font-size: 10px; font-weight: 700;
  letter-spacing: 0.5px; text-transform: uppercase; margin-bottom: 8px;
}
.tag.green  { background: rgba(61,214,140,0.12);  color: var(--correct); border: 1px solid rgba(61,214,140,0.3); }
.tag.amber  { background: rgba(255,165,2,0.12);   color: var(--warn);    border: 1px solid rgba(255,165,2,0.3); }
.tag.red    { background: rgba(255,71,87,0.1);    color: var(--wrong);   border: 1px solid rgba(255,71,87,0.3); }
.tag.purple { background: rgba(130,80,255,0.12);  color: #a78bfa;        border: 1px solid rgba(130,80,255,0.3); }
.tag.blue   { background: rgba(74,158,255,0.12);  color: var(--accent);  border: 1px solid rgba(74,158,255,0.3); }
.cheat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.cheat-card { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 20px; }
.cheat-card h3 {
  font-family: var(--font-display); font-size: 12px; font-weight: 700;
  letter-spacing: 0.5px; margin-bottom: 14px; color: var(--accent); text-transform: uppercase;
}
.cheat-row {
  display: flex; justify-content: space-between; align-items: flex-start;
  padding: 6px 0; border-bottom: 1px solid var(--border); font-size: 12px;
}
.cheat-row:last-child { border-bottom: none; }
.cheat-key { color: var(--muted); flex: 1; }
.cheat-val { color: var(--text); font-weight: 500; text-align: right; flex: 1; }

/* ── AB100 specific ── */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  margin-bottom: 24px;
}
.stat-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  text-align: center;
  transition: border-color 0.2s;
  cursor: pointer;
}
.stat-card:hover { border-color: var(--accent); }
.stat-card .stat-number, .stat-card .number {
  font-family: var(--font-display);
  font-size: 28px; font-weight: 900; color: var(--accent);
  display: block; margin-bottom: 4px;
}
.stat-card .stat-label, .stat-card .label {
  font-family: var(--font-mono); font-size: 10px; color: var(--dim);
  text-transform: uppercase; letter-spacing: 0.5px;
}
.controls {
  display: flex; gap: 12px; align-items: center; margin-bottom: 20px; flex-wrap: wrap;
}
.search-container { position: relative; flex: 1; min-width: 200px; }
.search-container input, input[type="search"], input[type="text"] {
  width: 100%; padding: 10px 16px;
  background: var(--card); border: 1px solid var(--border);
  border-radius: 10px; color: var(--text);
  font-family: var(--font-body); font-size: 14px;
  outline: none; transition: border-color 0.2s;
}
.search-container input:focus, input[type="search"]:focus, input[type="text"]:focus { border-color: var(--accent); }
.search-container input::placeholder { color: var(--dim); }
select {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 10px; color: var(--text);
  font-family: var(--font-body); font-size: 13px;
  padding: 10px 14px; cursor: pointer;
  outline: none;
}
select:focus { border-color: var(--accent); }
.score-summary {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 12px; padding: 16px 20px;
  display: flex; align-items: center; gap: 16px; margin-bottom: 20px; flex-wrap: wrap;
}
.score-fraction {
  font-family: var(--font-display); font-size: 20px; font-weight: 900; color: var(--text);
}
.pf-badge {
  padding: 4px 12px; border-radius: 20px;
  font-family: var(--font-mono); font-size: 11px; font-weight: 700;
}
.pf-badge.pass { background: rgba(61,214,140,0.12); color: var(--correct); border: 1px solid rgba(61,214,140,0.3); }
.pf-badge.fail { background: rgba(255,71,87,0.1);   color: var(--wrong);   border: 1px solid rgba(255,71,87,0.3); }
.question-container {
  display: flex; gap: 20px; flex: 1; min-height: 0;
}
.q-left { flex: 1; overflow-y: auto; }
.q-right {
  width: 260px; flex-shrink: 0;
  background: var(--card); border: 1px solid var(--border);
  border-radius: 14px; padding: 20px; overflow-y: auto;
}
.q-right h4 {
  font-family: var(--font-display); font-size: 11px; font-weight: 700;
  letter-spacing: 0.5px; color: var(--accent); text-transform: uppercase; margin-bottom: 12px;
}

/* ── Back to Exams link ── */
.back-link.back-link-standalone {
  display: block;
  max-width: 860px;
  margin: 1rem auto 0;
  padding: 0.75rem 20px;
}
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--accent);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.75rem 0;
  margin-bottom: 1rem;
  transition: opacity 0.2s;
  position: relative;
  z-index: 1;
}
.back-link:hover { opacity: 0.65; }

/* ── copilot wider container (aligns back button with edge) ── */
body.copilot .container {
  max-width: 1200px;
}

/* ── ab100 two-pane layout overrides ── */
body.ab100 .container {
  max-width: 1200px;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}
body.ab100 header { flex-shrink: 0; }

/* ── Utility ── */
.hidden { display: none !important; }

/* ── Responsive ── */
@media (max-width: 768px) {
  .question-container { flex-direction: column; }
  .q-right { width: 100%; }
}
@media (max-width: 600px) {
  .mode-grid, .grid-2, .grid-3, .cheat-grid { grid-template-columns: 1fr; }
  .question-card, .flash-card, .results-card, .results-screen { padding: 24px 20px; }
  .stats-row, .results-stats { gap: 20px; }
  .topic-row-name { min-width: 120px; font-size: 11px; }
  .results-btns { flex-direction: column; align-items: center; }
  .controls { flex-direction: column; }
  .top-nav { flex-direction: column; align-items: flex-start; }
}