:root {
  --bg: #f4f1ea;
  --paper: #fffdf8;
  --ink: #1d1b16;
  --muted: #6b6458;
  --line: #ddd6c8;
  --accent: #1f4b3a;
  --accent-soft: #e4efe8;
  --danger: #8a2f2f;
  --danger-soft: #f6e6e4;
  --ok: #1f4b3a;
  --ok-soft: #e4efe8;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Iowan Old Style", "Palatino Linotype", Palatino, "Songti TC", "Noto Serif TC", serif;
}

body {
  min-height: 100vh;
}

#app {
  max-width: 860px;
  margin: 0 auto;
  padding: 40px 20px 80px;
}

h1,
h2,
h3 {
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0 0 12px;
}

h1 {
  font-size: 40px;
  line-height: 1.15;
}

h2 {
  font-size: 24px;
  line-height: 1.4;
}

.eyebrow,
.meta,
.stat-label,
.progress-copy {
  color: var(--muted);
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 13px;
  letter-spacing: 0.04em;
}

.lead,
.explain,
.notice {
  line-height: 1.6;
}

.lead {
  color: var(--muted);
  max-width: 38em;
}

.lead a {
  color: var(--accent);
}

.verdict {
  font-size: 18px;
  letter-spacing: 0.08em;
  margin: 0 0 8px;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
}

.verdict.ok {
  color: var(--ok);
}

.verdict.bad {
  color: var(--danger);
}

.panel,
.question-card,
.review {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 28px;
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 28px 0;
}

.stats div {
  border-top: 1px solid var(--line);
  padding-top: 10px;
}

.stats strong {
  display: block;
  font-size: 28px;
  margin-top: 4px;
}

table.quota {
  width: 100%;
  border-collapse: collapse;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 14px;
}

table.quota th,
table.quota td {
  text-align: left;
  padding: 10px 8px;
  border-bottom: 1px solid var(--line);
}

table.quota th {
  color: var(--muted);
  font-weight: 500;
}

.actions,
.pager,
.exam-bar {
  display: flex;
  gap: 12px;
  align-items: center;
}

.actions {
  margin-top: 28px;
}

button {
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 14px;
  border: 1px solid var(--ink);
  background: transparent;
  color: var(--ink);
  padding: 10px 16px;
  cursor: pointer;
}

button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

button.ghost {
  background: transparent;
}

button.link {
  border: 0;
  padding: 0;
  text-decoration: underline;
  background: none;
}

button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

button.compact {
  padding: 8px 12px;
}

.notice {
  background: var(--danger-soft);
  color: var(--danger);
  padding: 12px 14px;
}

.exam-bar {
  justify-content: space-between;
  margin-bottom: 16px;
}

.nav-dots {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 18px;
}

.dot {
  min-width: 32px;
  padding: 6px 0;
  border-color: var(--line);
  color: var(--muted);
}

.dot.done {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
}

.dot.current {
  background: var(--ink);
  border-color: var(--ink);
  color: #fff;
}

.options {
  display: grid;
  gap: 10px;
  margin-top: 20px;
}

.option {
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 12px;
  text-align: left;
  width: 100%;
  padding: 14px;
}

.option span {
  font-weight: 600;
}

.option p {
  margin: 0;
  line-height: 1.5;
}

.option.selected {
  background: var(--accent-soft);
  border-color: var(--accent);
}

.pager {
  justify-content: space-between;
  margin-top: 18px;
}

.reviews {
  display: grid;
  gap: 16px;
  margin-top: 24px;
}

.review h3 {
  font-size: 20px;
}

.review ul {
  list-style: none;
  padding: 0;
  margin: 16px 0;
}

.review li {
  padding: 8px 0;
  border-bottom: 1px solid var(--line);
}

.review li.correct {
  background: var(--ok-soft);
}

.review li.wrong {
  background: var(--danger-soft);
}

.review li em {
  display: block;
  font-style: normal;
  font-size: 12px;
  color: var(--muted);
  margin-top: 4px;
}

.review.fail {
  border-color: #e2c7c4;
}

.answer-line {
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 14px;
  margin: 0 0 10px;
}

.explain {
  color: var(--muted);
}

.review-filters {
  display: flex;
  gap: 8px;
  margin: 16px 0 8px;
}

.notes {
  display: grid;
  gap: 20px;
  margin-top: 24px;
}

.notes-chapter {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 28px;
}

.notes-chapter h2 {
  font-size: 26px;
}

.notes-chapter h3 {
  font-size: 18px;
  margin-top: 20px;
}

ul.cues {
  margin: 8px 0 0;
  padding-left: 1.2em;
}

ul.cues li {
  margin: 6px 0;
  line-height: 1.55;
}

@media (max-width: 640px) {
  h1 {
    font-size: 32px;
  }

  .stats {
    grid-template-columns: 1fr;
  }

  .panel,
  .question-card,
  .review {
    padding: 20px;
  }
}