/* ---------- Tokens ---------- */
:root {
  --bg: #f6f5f1;
  --surface: #ffffff;
  --text: #1b2330;
  --muted: #4a5568;
  --border: #d3d8df;
  --accent: #1f5a5e;
  --accent-soft: #e4f0ef;
  --focus: #1a56db;
  --link: #1f5a5e;
  --link-visited: #5a3d86;

  --verified-bg: #e3f3e8;
  --verified-fg: #14532d;
  --verified-bd: #2f855a;
  --strong-bg: #e5eefb;
  --strong-fg: #1e3a8a;
  --strong-bd: #3b63b8;
  --inferred-bg: #fff3d6;
  --inferred-fg: #6b4100;
  --inferred-bd: #b7791f;
  --unknown-bg: #efeff1;
  --unknown-fg: #3a3a42;
  --unknown-bd: #6b6b76;
  --provisional-bg: #f1e8fb;
  --provisional-fg: #512678;
  --provisional-bd: #7e4bb0;

  --callout-unknown-bg: #fff8e7;
  --callout-unknown-bd: #b7791f;
  --callout-info-bg: #eaf2fb;
  --callout-info-bd: #3b63b8;

  --radius: 10px;
  --space: 1rem;
  --maxw: 70rem;
  --font: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #11151b;
    --surface: #1a2029;
    --text: #e8ebef;
    --muted: #a9b4c2;
    --border: #344152;
    --accent: #86cbc8;
    --accent-soft: #1d3334;
    --focus: #8ab4ff;
    --link: #8fd3cf;
    --link-visited: #c7a8f0;

    --verified-bg: #16301f;
    --verified-fg: #a7e3bb;
    --verified-bd: #3f9d63;
    --strong-bg: #172642;
    --strong-fg: #b7cdf7;
    --strong-bd: #5b82d1;
    --inferred-bg: #33280f;
    --inferred-fg: #f3d08a;
    --inferred-bd: #c58f2e;
    --unknown-bg: #262a31;
    --unknown-fg: #d4d6db;
    --unknown-bd: #8a8f99;
    --provisional-bg: #2b1f3b;
    --provisional-fg: #dcc3f7;
    --provisional-bd: #9a6fcc;

    --callout-unknown-bg: #2a2414;
    --callout-unknown-bd: #c58f2e;
    --callout-info-bg: #16233a;
    --callout-info-bd: #5b82d1;
  }
}

/* ---------- Base ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.6;
}

h1,
h2,
h3,
h4 {
  line-height: 1.25;
  margin: 1.6em 0 0.5em;
}
h1 {
  font-size: clamp(1.6rem, 1.2rem + 1.8vw, 2.3rem);
  margin-top: 0.4em;
}
h2 {
  font-size: 1.4rem;
}
h3 {
  font-size: 1.15rem;
}
h4 {
  font-size: 1rem;
}

p {
  margin: 0 0 0.85em;
}

a {
  color: var(--link);
  text-underline-offset: 0.18em;
}
a:visited {
  color: var(--link-visited);
}
a:hover {
  text-decoration-thickness: 2px;
}

code {
  font-family: ui-monospace, 'Cascadia Mono', Consolas, monospace;
  font-size: 0.9em;
  overflow-wrap: anywhere;
}

img {
  max-width: 100%;
  height: auto;
}

/* Visible focus for every interactive element and focus target. */
:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
  border-radius: 4px;
}
h1:focus,
h3[tabindex='-1']:focus,
main:focus {
  outline: none;
}
h1:focus-visible,
h3[tabindex='-1']:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 4px;
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: 0.75rem;
  top: -4rem;
  z-index: 10;
  background: var(--surface);
  color: var(--text);
  padding: 0.6rem 1rem;
  border: 2px solid var(--focus);
  border-radius: var(--radius);
}
.skip-link:focus {
  top: 0.75rem;
}

.muted {
  color: var(--muted);
}
.small {
  font-size: 0.92rem;
}

/* ---------- Shell ---------- */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}
.site-header__inner,
.nav,
.main,
.site-footer p {
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--space);
}
.site-header__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.25rem 1rem;
  padding-block: 0.85rem 0.35rem;
}
.brand {
  display: flex;
  flex-wrap: wrap;
  gap: 0 0.5rem;
  align-items: baseline;
  text-decoration: none;
  color: var(--text);
}
.brand:visited {
  color: var(--text);
}
.brand__code {
  font-weight: 800;
  color: var(--accent);
  letter-spacing: 0.02em;
}
.brand__title {
  font-weight: 650;
}
.brand__meta {
  margin: 0;
  font-size: 0.9rem;
  color: var(--muted);
}
.site-header__aside {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.25rem 1rem;
}
.home-link,
.home-link:visited {
  font-size: 0.9rem;
  color: var(--link);
  text-decoration: none;
}
.home-link:hover {
  text-decoration: underline;
}

.nav__list {
  list-style: none;
  margin: 0;
  padding: 0.25rem 0 0.6rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}
.nav__link {
  display: inline-block;
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  text-decoration: none;
  color: var(--text);
  border: 1px solid transparent;
  font-size: 0.95rem;
}
.nav__link:visited {
  color: var(--text);
}
.nav__link:hover {
  border-color: var(--border);
}
.nav__link[aria-current='page'] {
  background: var(--accent-soft);
  border-color: var(--accent);
  font-weight: 650;
}

.main {
  padding-block: 1.25rem 3rem;
}

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  font-size: 0.9rem;
}
.site-footer p {
  padding-block: 1rem;
  margin: 0 auto;
}

/* ---------- Page components ---------- */
.page > section {
  margin-top: 2rem;
}
.eyebrow {
  margin: 0;
  color: var(--muted);
  font-weight: 600;
  font-size: 0.95rem;
}
.lede {
  font-size: 1.12rem;
  max-width: 44rem;
}

.breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  font-size: 0.92rem;
  color: var(--muted);
}
.breadcrumb li + li::before {
  content: '›';
  margin-right: 0.35rem;
  color: var(--muted);
}

.badge {
  display: inline-block;
  padding: 0.05rem 0.55rem;
  border-radius: 999px;
  border: 1px solid;
  font-size: 0.85rem;
  line-height: 1.55;
  white-space: nowrap;
}
.badge strong {
  font-weight: 700;
}
.badge--verified {
  background: var(--verified-bg);
  color: var(--verified-fg);
  border-color: var(--verified-bd);
}
.badge--strongly-supported {
  background: var(--strong-bg);
  color: var(--strong-fg);
  border-color: var(--strong-bd);
}
.badge--inferred {
  background: var(--inferred-bg);
  color: var(--inferred-fg);
  border-color: var(--inferred-bd);
}
.badge--unknown {
  background: var(--unknown-bg);
  color: var(--unknown-fg);
  border-color: var(--unknown-bd);
  border-style: dashed;
}
.badge--provisional {
  background: var(--provisional-bg);
  color: var(--provisional-fg);
  border-color: var(--provisional-bd);
}
.badge-row {
  list-style: none;
  padding: 0;
  margin: 0.25rem 0 0.75rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.callout {
  border: 1px solid var(--border);
  border-left: 5px solid;
  border-radius: var(--radius);
  padding: 0.9rem 1.1rem 0.4rem;
  margin: 1.25rem 0;
  max-width: 50rem;
}
.callout--unknown {
  background: var(--callout-unknown-bg);
  border-left-color: var(--callout-unknown-bd);
}
.callout--info {
  background: var(--callout-info-bg);
  border-left-color: var(--callout-info-bd);
}
.callout__title {
  font-weight: 750;
  margin-bottom: 0.35rem;
}
.callout__subtitle {
  font-weight: 650;
  margin-bottom: 0.2rem;
}
.callout ul {
  margin-top: 0;
}

.card-grid {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.9rem;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 15rem), 1fr));
}
.card-grid--two {
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 22rem), 1fr));
}
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.1rem 0.5rem;
}
.card__title {
  margin-top: 0;
}

.claim-list,
.fact-list,
.mapping-list,
.claim-cards,
.source-list,
.link-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.claim-list li {
  padding: 0.6rem 0;
  border-bottom: 1px solid var(--border);
}
.claim-list li p {
  margin-bottom: 0.3rem;
}
.link-list li {
  padding: 0.3rem 0;
}

.fact-list {
  display: grid;
  gap: 0.75rem;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 19rem), 1fr));
}
.fact,
.mapping,
.claim,
.source {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.8rem 1rem 0.4rem;
}
.claim,
.source,
.mapping {
  margin-bottom: 0.75rem;
}
.fact__head {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: baseline;
  gap: 0.4rem 0.75rem;
}
.fact__label {
  margin: 0;
  font-size: 1rem;
}
.fact__value {
  margin: 0.35rem 0 0.4rem;
}

/* Evidence details */
.evidence {
  margin: 0.5rem 0 0.75rem;
  border-top: 1px dashed var(--border);
  padding-top: 0.4rem;
}
.evidence summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 0.93rem;
  color: var(--link);
  padding: 0.2rem 0;
  width: fit-content;
}
.citation-list {
  list-style: none;
  padding: 0;
  margin: 0.4rem 0 0;
}
.citation {
  padding: 0.5rem 0.75rem;
  border-left: 3px solid var(--border);
  margin-bottom: 0.5rem;
}
.citation__title {
  font-weight: 600;
  margin-bottom: 0.2rem;
}
.citation__meta {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 0.1rem 0.75rem;
  margin: 0 0 0.5rem;
  font-size: 0.9rem;
}
.citation__meta dt {
  color: var(--muted);
}
.citation__meta dd {
  margin: 0;
  overflow-wrap: anywhere;
}
@media (max-width: 30rem) {
  .citation__meta {
    grid-template-columns: 1fr;
  }
  .citation__meta dd {
    margin-bottom: 0.35rem;
  }
}

/* Outline */
.outline-domain {
  border-top: 2px solid var(--border);
}
.outline-cluster {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.25rem 1.1rem 0.5rem;
  margin: 0.9rem 0;
}
.objective-list {
  padding-left: 1.4rem;
}
.objective-list li {
  margin-bottom: 0.5rem;
}
.objective-list li p {
  margin-bottom: 0.15rem;
}

/* Study unit */
.unit .study-section {
  max-width: 46rem;
}
.unit > p,
.unit > section > p {
  max-width: 46rem;
}
.objective-tag {
  background: var(--accent-soft);
  border-radius: 6px;
  padding: 0.35rem 0.65rem;
}
.support-panel {
  display: grid;
  gap: 0.9rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 18rem), 1fr));
}
.support-panel__col {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.25rem 1rem 0.3rem;
}
.support-panel__col h3 {
  margin-top: 0.75rem;
}
.relevance-list {
  list-style: none;
  padding: 0;
  margin: 0 0 0.75rem;
  display: grid;
  gap: 0.3rem;
}
.figure {
  margin: 1.25rem 0;
  max-width: 26rem;
}
.figure img {
  display: block;
  width: 100%;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #ffffff;
}
.figure figcaption {
  font-size: 0.92rem;
  color: var(--muted);
  margin-top: 0.5rem;
}
.key-points {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.1rem 1rem 0.2rem;
  margin: 1rem 0;
}
.key-points h3 {
  margin-top: 0.7rem;
  font-size: 1rem;
}
.glossary dt {
  font-weight: 700;
  margin-top: 1rem;
}
.glossary dd {
  margin: 0.2rem 0 0;
  max-width: 46rem;
}
.glossary dd p {
  margin-bottom: 0.2rem;
}

/* Sources */
.status-key {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 0.5rem 1rem;
  align-items: baseline;
}
.status-key dd {
  margin: 0;
}
@media (max-width: 30rem) {
  .status-key {
    grid-template-columns: 1fr;
    gap: 0.2rem;
  }
  .status-key dd {
    margin-bottom: 0.6rem;
  }
}
.source h3 {
  margin-top: 0.3rem;
}
.source h4 {
  margin: 0.6rem 0 0.2rem;
  font-size: 0.95rem;
}
.source ul {
  margin-top: 0;
}
.issue-list li {
  margin-bottom: 0.5rem;
}

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}

/* Practice */
.practice-actions { display: flex; flex-wrap: wrap; gap: 0.65rem; margin: 1rem 0; }
.practice button, .exam-page button {
  font: inherit; color: var(--text); background: var(--surface);
  border: 2px solid var(--accent); border-radius: 7px; padding: 0.45rem 0.75rem;
  cursor: pointer; max-width: 100%; text-align: left;
}
.practice button:hover, .exam-page button:hover:not(:disabled) { background: var(--accent-soft); }
.exam-page button:disabled { opacity: 0.55; cursor: default; }
.practice-count { font-weight: 700; }
.question-nav { display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 1rem 0; }
.question-nav button { font-size: 0.9rem; border-color: var(--border); }
.question-nav button.is-current { border-color: var(--accent); background: var(--accent-soft); font-weight: 700; }
.question-card, .review-item {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 0.8rem 1rem; margin: 1rem 0;
}
.question-card { max-width: 52rem; }
.question-card h2 { margin-top: 0.35rem; }
.answer-field { border: 0; padding: 0; margin: 1rem 0; min-width: 0; }
.answer-field legend { font-weight: 700; padding: 0; margin-bottom: 0.5rem; }
.answer-option {
  display: flex; align-items: flex-start; gap: 0.65rem; cursor: pointer;
  border: 1px solid var(--border); border-radius: 7px;
  padding: 0.55rem 0.7rem; margin: 0.45rem 0;
}
.answer-option:has(input:checked) { background: var(--accent-soft); border-color: var(--accent); }
.answer-option input { margin-top: 0.42rem; flex: none; }
.result-score { font-size: 1.5rem; font-weight: 800; }
.review-list { padding-left: 1.5rem; }
.review-item { padding-left: 1.2rem; }
.review-item h3 { margin-top: 0.25rem; }
.review-study { border-left: 4px solid var(--accent); padding-left: 0.8rem; }

/* Exam */
.exam-scope, .question-map { margin: 1rem 0; max-width: 52rem; }
.exam-scope summary, .question-map summary { cursor: pointer; font-weight: 700; }
.exam-table { border-collapse: collapse; margin: 0.75rem 0; width: 100%; max-width: 52rem; }
.exam-table caption { text-align: left; font-weight: 700; padding-bottom: 0.35rem; }
.exam-table th, .exam-table td { border: 1px solid var(--border); padding: 0.4rem 0.55rem; text-align: left; vertical-align: top; }
.exam-table thead th { background: var(--accent-soft); }
.table-scroll { overflow-x: auto; max-width: 100%; }
.exam-exhibit { margin: 0.75rem 0; font-weight: 400; }
.exam-exhibit th[scope="row"] { font-weight: 600; }
@media (max-width: 30rem) {
  .exam-exhibit .exam-table { font-size: 0.88rem; }
  .exam-exhibit .exam-table th, .exam-exhibit .exam-table td { padding: 0.3rem 0.35rem; }
}
.exam-exhibit img { max-width: 100%; height: auto; background: #fff; border: 1px solid var(--border); border-radius: 7px; }
.exam-exhibit figcaption { font-size: 0.9rem; color: var(--muted); margin-top: 0.3rem; }
.question-map__list { list-style: none; padding: 0; margin: 0.6rem 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(2.6rem, 1fr)); gap: 0.35rem; }
.exam-page .question-map__item { width: 100%; text-align: center; padding: 0.3rem 0; font-size: 0.9rem; border-color: var(--border); }
.exam-page .question-map__item.is-answered { background: var(--accent-soft); }
.exam-page .question-map__item.is-correct { background: var(--verified-bg); color: var(--verified-fg); border-color: var(--verified-bd); }
.exam-page .question-map__item.is-incorrect { background: var(--inferred-bg); color: var(--inferred-fg); border-color: var(--inferred-bd); text-decoration: line-through; }
.exam-page .question-map__item.is-unanswered { border-style: dashed; }
.exam-page .question-map__item.is-current { outline: 3px solid var(--accent); outline-offset: 1px; font-weight: 800; }
.answer-option__letter { font-weight: 700; min-width: 1.3rem; }
.exam-review__stem { font-weight: 700; }
.exam-outcome.is-correct { color: var(--verified-fg); }
.exam-outcome.is-incorrect, .exam-outcome.is-unanswered { color: var(--inferred-fg); }
.exam-options { padding-left: 1.6rem; }
.exam-option { border: 1px solid var(--border); border-radius: 7px; padding: 0.35rem 0.7rem; margin: 0.45rem 0; }
.exam-option p { margin: 0.25rem 0; }
.exam-option.is-key { border: 2px solid var(--verified-bd); background: var(--verified-bg); color: var(--verified-fg); }
.exam-option.is-wrong { border: 2px solid var(--inferred-bd); background: var(--inferred-bg); color: var(--inferred-fg); }
.exam-takeaway { border-left: 4px solid var(--accent); padding-left: 0.8rem; }
.exam-sources { padding-left: 1.2rem; }
.jump { display: inline-flex; align-items: center; gap: 0.4rem; }
.jump input { width: 4.5rem; font: inherit; padding: 0.3rem; }