:root {
  --bg: #f5f6f8;
  --card: #ffffff;
  --text: #1c2230;
  --muted: #5c6470;
  --border: #dde1e7;
  --accent: #1f5eff;
  --accent-contrast: #ffffff;
  --correct: #1a8a4a;
  --incorrect: #d1372f;
  --warn-bg: #fff6df;
  --warn-border: #e8c766;
  --radius: 10px;
}

* { box-sizing: border-box; }

[hidden] { display: none !important; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.45;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 5;
  background: var(--card);
  border-bottom: 1px solid var(--border);
}

.topbar-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.topbar-inner h1 {
  font-size: 1.15rem;
  margin: 0;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.timer {
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  color: var(--muted);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 4px 12px;
}

.btn {
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 10px 18px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.15s ease;
}
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-primary { background: var(--accent); color: var(--accent-contrast); }
.btn-primary:hover:not(:disabled) { opacity: 0.9; }
.btn-ghost { background: transparent; color: var(--accent); border-color: var(--border); }
.btn-ghost:hover { background: var(--bg); }

main.screen {
  max-width: 900px;
  margin: 0 auto;
  padding: 24px 20px 80px;
}

.setup {
  display: flex;
  justify-content: center;
  padding-top: 60px;
}

.setup-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  max-width: 480px;
  width: 100%;
}

.setup-card h2 { margin-top: 0; }

.setup-card label {
  display: block;
  font-weight: 600;
  margin-bottom: 6px;
  margin-top: 18px;
}

.setup-card input[type="number"] {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 1rem;
}

.topic-actions {
  display: flex;
  gap: 14px;
  margin-top: 2px;
}

.btn-link {
  background: none;
  border: none;
  padding: 0;
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
}
.btn-link:hover { text-decoration: underline; }

.topic-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
  max-height: 260px;
  overflow-y: auto;
  margin-top: 8px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
}

.topic-option {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 4px;
  font-weight: 400;
  font-size: 0.9rem;
  cursor: pointer;
  margin: 0;
}
.topic-option:hover { background: var(--bg); }
.topic-option span:nth-child(2) { flex: 1; }

.topic-count {
  color: var(--muted);
  font-size: 0.8rem;
}

.bank-info {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 12px 0 4px;
}

.setup-card .btn {
  width: 100%;
  margin-top: 20px;
}

.question-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.question-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.question-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 10px;
}

.question-number {
  font-weight: 700;
  color: var(--muted);
}

.question-topic {
  font-size: 0.75rem;
  color: var(--muted);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 2px 10px;
  white-space: nowrap;
}

.question-text {
  font-size: 1.02rem;
  margin: 0 0 14px;
}

.question-image {
  max-width: 100%;
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 14px;
  display: block;
}

.options {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
}

.option:hover { background: var(--bg); }
.option input { margin-top: 3px; }

.option.correct { border-color: var(--correct); background: #eafaf0; }
.option.incorrect { border-color: var(--incorrect); background: #fdecea; }

.option-note {
  font-size: 0.8rem;
  font-weight: 700;
  margin-left: auto;
  white-space: nowrap;
}
.option.correct .option-note { color: var(--correct); }
.option.incorrect .option-note { color: var(--incorrect); }

.numeric-answer {
  display: flex;
}
.numeric-answer label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
}
.numeric-answer input {
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 1rem;
  width: 160px;
}
.numeric-answer input:disabled {
  background: var(--bg);
  color: var(--text);
  opacity: 1;
}

.numeric-correct { border-color: var(--correct); background: #eafaf0; color: var(--correct); font-weight: 700; }
.numeric-incorrect { border-color: var(--incorrect); background: #fdecea; color: var(--incorrect); font-weight: 700; }

.flag-note {
  margin-top: 12px;
  font-size: 0.85rem;
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  border-radius: 8px;
  padding: 8px 12px;
  color: #6b5400;
}

.submit-bar {
  position: sticky;
  bottom: 0;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 20px;
  margin-top: 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.progress { color: var(--muted); font-size: 0.9rem; }

.results-summary {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
}

.score-line { font-size: 1.4rem; font-weight: 700; }

.flagged-box {
  text-align: left;
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  border-radius: 8px;
  padding: 16px 20px;
  margin: 20px 0;
}
.flagged-box h3 { margin-top: 0; }
.flagged-box li { margin-bottom: 6px; }

.results-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-top: 20px;
}

#reviewList { margin-top: 24px; }

.modal {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: center;
}
.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
}
.modal-content {
  position: relative;
  background: var(--card);
  border-radius: var(--radius);
  padding: 16px;
  max-width: 92vw;
  max-height: 92vh;
  overflow: auto;
}
.modal-content img { max-width: 100%; display: block; }
.modal-close {
  position: absolute;
  top: 8px;
  right: 12px;
  background: none;
  border: none;
  font-size: 1.6rem;
  line-height: 1;
  cursor: pointer;
  color: var(--muted);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161c;
    --card: #1c1f27;
    --text: #eceef2;
    --muted: #9aa2b1;
    --border: #2c3140;
    --warn-bg: #332b12;
    --warn-border: #6b5a1f;
  }
  .option.correct { background: #123423; }
  .option.incorrect { background: #3a1a18; }
  .flag-note { color: #e7d38a; }
  .numeric-correct { background: #123423; }
  .numeric-incorrect { background: #3a1a18; }
}