:root {
  --bg: #f6f0e4;
  --bg-deep: #eadfcb;
  --surface: rgba(255, 251, 244, 0.88);
  --surface-strong: #fff8ee;
  --line: rgba(75, 54, 38, 0.18);
  --line-strong: rgba(75, 54, 38, 0.32);
  --ink: #241c18;
  --muted: #655448;
  --accent: #bb4c2f;
  --accent-soft: #f5d7cd;
  --accent-deep: #84301d;
  --success: #1f7a4e;
  --success-soft: #d9efe3;
  --warning: #94671a;
  --warning-soft: #f6e6bb;
  --danger: #b63428;
  --danger-soft: #f7d8d4;
  --shadow: 0 24px 60px rgba(53, 34, 20, 0.12);
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-sm: 12px;
  --max-width: 1240px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Aptos", "Trebuchet MS", "Segoe UI", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.75), transparent 34%),
    radial-gradient(circle at top right, rgba(187, 76, 47, 0.12), transparent 28%),
    linear-gradient(180deg, var(--bg) 0%, #f1e8d9 58%, var(--bg-deep) 100%);
}

a {
  color: var(--accent-deep);
}

a.action-pill,
a.reference-link,
a.chapter-nav-link,
a.chapter-back-link {
  text-decoration: none;
}

button,
input {
  font: inherit;
}

.page-shell {
  width: min(calc(100% - 2rem), var(--max-width));
  margin: 0 auto;
  padding: 2rem 0 3rem;
}

.hero {
  display: grid;
  grid-template-columns: 1.3fr 0.9fr;
  gap: 1.5rem;
  align-items: stretch;
}

.hero-copy,
.hero-panel,
.summary-zone,
.toolbar,
.question-card,
.page-footer {
  background: var(--surface);
  backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.hero-copy {
  position: relative;
  overflow: hidden;
  padding: 2rem;
  border-radius: var(--radius-lg);
}

.hero-copy::after {
  content: "";
  position: absolute;
  inset: auto -6rem -6rem auto;
  width: 16rem;
  height: 16rem;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(187, 76, 47, 0.18), transparent 68%);
}

.eyebrow {
  margin: 0 0 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--accent-deep);
  font-size: 0.78rem;
  font-weight: 700;
}

h1,
h2,
h3 {
  font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Georgia, serif;
  line-height: 1.05;
}

h1 {
  margin: 0;
  font-size: clamp(2.3rem, 4vw, 4.2rem);
}

.lead {
  max-width: 48rem;
  margin: 1rem 0 0;
  font-size: 1.08rem;
  line-height: 1.6;
  color: var(--muted);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.action-pill,
.filter-pill,
.question-button {
  border: 1px solid transparent;
  transition:
    transform 180ms ease,
    background-color 180ms ease,
    border-color 180ms ease,
    color 180ms ease,
    box-shadow 180ms ease;
}

.action-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1rem;
  border-radius: 999px;
  background: #fff5ef;
  color: var(--accent-deep);
  cursor: pointer;
  font-weight: 700;
}

.action-pill:hover,
.action-pill:focus-visible,
.filter-pill:hover,
.filter-pill:focus-visible,
.question-button:hover,
.question-button:focus-visible {
  transform: translateY(-1px);
  outline: none;
}

.action-pill.is-active {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 12px 24px rgba(187, 76, 47, 0.24);
}

.action-pill-muted {
  background: rgba(255, 255, 255, 0.7);
  color: var(--ink);
  border-color: var(--line);
}

.hero-panel {
  padding: 1.5rem;
  border-radius: var(--radius-lg);
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem;
}

.stat-card {
  padding: 1rem;
  border-radius: var(--radius-md);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.95), rgba(248, 241, 232, 0.82));
  border: 1px solid var(--line);
}

.stat-label {
  display: block;
  color: var(--muted);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.stat-value {
  display: block;
  margin-top: 0.35rem;
  font-size: clamp(1.2rem, 2vw, 1.6rem);
}

.mode-description {
  margin: 1rem 0 0;
  padding: 1rem 1.1rem;
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: rgba(255, 245, 239, 0.9);
  color: var(--muted);
  line-height: 1.6;
}

.toolbar {
  margin-top: 1.5rem;
  padding: 1.4rem 1.5rem;
  border-radius: var(--radius-lg);
}

.summary-zone {
  margin-top: 1.5rem;
  padding: 1.4rem 1.5rem;
  border-radius: var(--radius-lg);
}

.toolbar-copy h2 {
  margin: 0;
  font-size: 1.4rem;
}

.toolbar-copy p {
  margin: 0.5rem 0 0;
  color: var(--muted);
  line-height: 1.5;
}

.topic-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1rem;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.summary-card {
  padding: 1.1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(246, 238, 227, 0.84));
  animation: card-rise 420ms ease both;
  animation-delay: calc(var(--stagger, 0) * 32ms);
}

.summary-head {
  display: grid;
  gap: 0.35rem;
}

.summary-label {
  margin: 0;
  color: var(--accent-deep);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-weight: 700;
}

.summary-title {
  margin: 0;
  font-size: 1.45rem;
}

.summary-lead {
  margin: 0.75rem 0 0;
  color: var(--muted);
  line-height: 1.55;
}

.summary-block {
  margin-top: 1rem;
  padding: 0.95rem 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.72);
}

.summary-block-warning {
  border-color: rgba(148, 103, 26, 0.22);
  background: rgba(246, 230, 187, 0.42);
}

.summary-block-title {
  margin: 0;
  color: var(--accent-deep);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.11em;
  font-weight: 700;
}

.summary-list {
  margin: 0.7rem 0 0;
  padding-left: 1.1rem;
  display: grid;
  gap: 0.55rem;
}

.summary-list li {
  line-height: 1.5;
}

.filter-pill {
  padding: 0.65rem 0.95rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.85);
  border-color: var(--line);
  color: var(--ink);
  cursor: pointer;
  font-weight: 700;
}

.filter-pill.is-active {
  background: #2f2824;
  color: #fff;
  border-color: #2f2824;
}

.question-grid {
  display: grid;
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.question-card {
  border-radius: var(--radius-lg);
  padding: 1.35rem;
  animation: card-rise 420ms ease both;
  animation-delay: calc(var(--stagger, 0) * 48ms);
}

.question-head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: flex-start;
}

.question-index {
  margin: 0 0 0.45rem;
  color: var(--accent-deep);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 700;
}

.question-title {
  margin: 0;
  font-size: clamp(1.2rem, 2vw, 1.55rem);
}

.question-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.45rem;
}

.meta-pill {
  padding: 0.45rem 0.75rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.78);
  font-size: 0.83rem;
  color: var(--muted);
  white-space: nowrap;
}

.meta-pill.is-theme {
  color: var(--accent-deep);
  border-color: rgba(187, 76, 47, 0.24);
  background: rgba(245, 215, 205, 0.7);
}

.choice-list {
  display: grid;
  gap: 0.75rem;
  margin-top: 1.2rem;
}

.choice {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.8rem;
  align-items: flex-start;
  padding: 0.95rem 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.76);
  cursor: pointer;
  transition:
    transform 160ms ease,
    border-color 160ms ease,
    background-color 160ms ease;
}

.choice:hover {
  transform: translateY(-1px);
  border-color: var(--line-strong);
}

.choice input {
  margin: 0.2rem 0 0;
  accent-color: var(--accent);
}

.choice-text {
  line-height: 1.5;
}

.choice.is-correct {
  border-color: rgba(31, 122, 78, 0.38);
  background: var(--success-soft);
}

.choice.is-missed {
  border-color: rgba(148, 103, 26, 0.38);
  background: var(--warning-soft);
}

.choice.is-incorrect {
  border-color: rgba(182, 52, 40, 0.36);
  background: var(--danger-soft);
}

.choice.is-selected {
  box-shadow: inset 0 0 0 1px rgba(187, 76, 47, 0.18);
}

.question-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1rem;
}

.question-button {
  padding: 0.75rem 1rem;
  border-radius: 999px;
  border-color: rgba(187, 76, 47, 0.2);
  background: rgba(255, 245, 239, 0.94);
  color: var(--accent-deep);
  cursor: pointer;
  font-weight: 700;
}

.question-button-secondary {
  border-color: var(--line);
  background: rgba(255, 255, 255, 0.72);
  color: var(--ink);
}

.feedback {
  margin-top: 1rem;
  padding: 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.78);
}

.feedback.is-success {
  border-color: rgba(31, 122, 78, 0.36);
  background: rgba(217, 239, 227, 0.88);
}

.feedback.is-warning {
  border-color: rgba(148, 103, 26, 0.35);
  background: rgba(246, 230, 187, 0.88);
}

.feedback.is-danger {
  border-color: rgba(182, 52, 40, 0.35);
  background: rgba(247, 216, 212, 0.88);
}

.feedback-title {
  margin: 0;
  font-size: 1.05rem;
}

.feedback-copy,
.feedback-explanation {
  margin: 0.55rem 0 0;
  line-height: 1.6;
  color: #3f352f;
}

.reference-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 0.9rem;
}

.reference-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 0.75rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.92);
  color: var(--accent-deep);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 700;
}

.chapter-page {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 1.5rem;
  margin-top: 1.5rem;
  align-items: start;
}

.chapter-nav-wrap {
  position: sticky;
  top: 1rem;
}

.chapter-nav-card,
.chapter-card {
  background: var(--surface);
  backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.chapter-nav-card {
  padding: 1.35rem;
  border-radius: var(--radius-lg);
}

.chapter-nav {
  display: grid;
  gap: 0.7rem;
  margin-top: 1rem;
}

.chapter-nav-link {
  display: grid;
  gap: 0.25rem;
  padding: 0.8rem 0.9rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.8);
  color: var(--ink);
  transition:
    transform 160ms ease,
    border-color 160ms ease,
    background-color 160ms ease;
}

.chapter-nav-link:hover,
.chapter-nav-link:focus-visible {
  transform: translateY(-1px);
  border-color: var(--line-strong);
  background: rgba(255, 245, 239, 0.92);
  outline: none;
}

.chapter-nav-kicker {
  color: var(--accent-deep);
  font-size: 0.76rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 700;
}

.chapter-cards {
  display: grid;
  gap: 1.25rem;
}

.chapter-card {
  padding: 1.4rem;
  border-radius: var(--radius-lg);
  animation: card-rise 420ms ease both;
  animation-delay: calc(var(--stagger, 0) * 34ms);
}

.chapter-head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: flex-start;
}

.chapter-title {
  margin: 0.2rem 0 0;
  font-size: clamp(1.45rem, 2.4vw, 2rem);
}

.chapter-back-link {
  white-space: nowrap;
  color: var(--accent-deep);
  font-weight: 700;
}

.chapter-lead {
  margin: 0.9rem 0 0;
  color: var(--muted);
  line-height: 1.65;
  font-size: 1.04rem;
}

.chapter-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.chapter-section {
  padding: 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.78);
}

.chapter-section-warning {
  border-color: rgba(148, 103, 26, 0.28);
  background: rgba(246, 230, 187, 0.48);
}

.chapter-section-soft {
  border-color: rgba(187, 76, 47, 0.18);
  background: rgba(255, 245, 239, 0.84);
}

.chapter-section-title {
  margin: 0;
  color: var(--accent-deep);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 700;
}

.page-footer {
  margin-top: 1.5rem;
  padding: 1rem 1.2rem;
  border-radius: var(--radius-lg);
}

.page-footer p {
  margin: 0;
  color: var(--muted);
  line-height: 1.6;
}

.empty-state {
  padding: 2rem;
  border-radius: var(--radius-lg);
  border: 1px dashed var(--line-strong);
  background: rgba(255, 255, 255, 0.7);
  text-align: center;
  color: var(--muted);
}

@keyframes card-rise {
  from {
    opacity: 0;
    transform: translateY(14px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 920px) {
  .hero {
    grid-template-columns: 1fr;
  }

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

  .chapter-page {
    grid-template-columns: 1fr;
  }

  .chapter-nav-wrap {
    position: static;
  }

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

  .question-head {
    flex-direction: column;
  }

  .question-meta {
    justify-content: flex-start;
  }
}

@media (max-width: 640px) {
  .page-shell {
    width: min(calc(100% - 1rem), var(--max-width));
    padding-top: 1rem;
  }

  .hero-copy,
  .hero-panel,
  .summary-zone,
  .toolbar,
  .question-card,
  .page-footer {
    border-radius: 22px;
  }

  .hero-copy,
  .hero-panel,
  .summary-zone,
  .toolbar,
  .question-card {
    padding: 1rem;
  }

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

  .action-pill,
  .filter-pill,
  .question-button {
    width: 100%;
    justify-content: center;
  }

  .hero-actions,
  .question-actions {
    flex-direction: column;
  }

  .reference-list {
    flex-direction: column;
  }

  .chapter-head {
    flex-direction: column;
  }

  .chapter-nav-card,
  .chapter-card {
    border-radius: 22px;
  }
}