/* the science of: shared stylesheet */

@import url('https://fonts.googleapis.com/css2?family=Lora:ital,wght@0,500;0,600;0,700;1,500&family=Source+Sans+3:wght@400;500;600&display=swap');

:root {
  --ink: #2a2825;
  --paper: #e9e5db;
  --card: #f2efe6;
  --navy: #3e5a6c;
  --navy-dark: #2b3f4c;
  --gold: #a37b4c;
  --line: #d3cbb9;
  --muted: #66604f;
  --max-w: 780px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: 'Source Sans 3', system-ui, -apple-system, sans-serif;
  font-size: 17px;
  line-height: 1.65;
}

h1, h2, h3, .brand {
  font-family: 'Lora', Georgia, serif;
  color: var(--navy-dark);
  line-height: 1.25;
}

a { color: var(--navy); }
a:hover { color: var(--gold); }

/* ---------- reading progress bar ---------- */
#progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: var(--gold);
  z-index: 999;
  transition: width .08s linear;
}

/* ---------- header ---------- */
header.site {
  border-bottom: 3px solid var(--navy-dark);
  background: var(--card);
}

.site-inner {
  max-width: 1000px;
  margin: 0 auto;
  padding: 18px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.brand {
  font-size: 22px;
  font-weight: 700;
  text-decoration: none;
  color: var(--navy-dark);
  letter-spacing: 0.2px;
}

.brand span {
  color: var(--gold);
}

nav.main-nav {
  display: flex;
  gap: 22px;
  flex-wrap: wrap;
  font-size: 15px;
}

nav.main-nav a {
  text-decoration: none;
  color: var(--ink);
  font-weight: 600;
  padding-bottom: 3px;
  border-bottom: 2px solid transparent;
}

nav.main-nav a.active,
nav.main-nav a:hover {
  color: var(--navy);
  border-bottom-color: var(--gold);
}

/* ---------- hero ---------- */
.hero {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 56px 24px 24px;
}

.hero .kicker {
  text-transform: uppercase;
  letter-spacing: 1.5px;
  font-size: 13px;
  font-weight: 600;
  color: var(--gold);
  margin-bottom: 10px;
}

.hero h1 {
  font-size: 38px;
  margin: 0 0 16px;
}

.hero p.lede {
  font-size: 19px;
  color: var(--muted);
  max-width: 62ch;
}

/* ---------- quick fact widget (home) ---------- */
.fact-widget {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px 8px;
}

.fact-widget-inner {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 22px 24px;
}

.fact-widget .tag {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--gold);
  margin-bottom: 8px;
}

#fact-text {
  margin: 0 0 14px;
  font-size: 16px;
  color: var(--ink);
  min-height: 44px;
}

#fact-btn {
  font-family: 'Source Sans 3', sans-serif;
  font-size: 14.5px;
  font-weight: 600;
  color: #fff;
  background: var(--navy);
  border: none;
  border-radius: 6px;
  padding: 10px 18px;
  cursor: pointer;
  transition: background .15s ease;
}

#fact-btn:hover { background: var(--navy-dark); }

/* ---------- topic grid (home) ---------- */
.topic-grid {
  max-width: 1000px;
  margin: 8px auto 64px;
  padding: 0 24px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.topic-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 24px;
  text-decoration: none;
  color: inherit;
  display: block;
  transition: border-color .15s ease, transform .15s ease, box-shadow .15s ease;
}

.topic-card:hover {
  border-color: var(--navy);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(43, 63, 76, 0.12);
}

.topic-card .tag {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--gold);
}

.topic-card h3 {
  margin: 8px 0 8px;
  font-size: 21px;
}

.topic-card p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
}

/* ---------- article content ---------- */
main.page {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 48px 24px 24px;
}

main.page h1 { font-size: 32px; margin-bottom: 6px; }

.page-intro {
  color: var(--muted);
  font-size: 18px;
  margin-bottom: 40px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--line);
}

article.section {
  margin-bottom: 40px;
}

article.section h2 {
  font-size: 24px;
  margin-bottom: 10px;
}

article.section p {
  margin: 0 0 14px;
}

sup.cite a {
  text-decoration: none;
  font-weight: 700;
  color: var(--navy);
  background: #e4e9ea;
  border-radius: 4px;
  padding: 1px 5px;
  font-size: 12px;
}

sup.cite a:hover { background: var(--gold); color: #fff; }

.callout {
  background: #e3ddc9;
  border-left: 4px solid var(--gold);
  padding: 16px 20px;
  border-radius: 6px;
  margin: 24px 0;
  font-size: 15.5px;
}

.callout strong { color: var(--navy-dark); }

/* ---------- quiz widget ---------- */
.quiz {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 22px 24px;
  margin: 32px 0;
}

.quiz-q {
  font-family: 'Lora', Georgia, serif;
  font-weight: 600;
  color: var(--navy-dark);
  margin-bottom: 14px;
  font-size: 17px;
}

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

.quiz-option {
  text-align: left;
  font-family: 'Source Sans 3', sans-serif;
  font-size: 15px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 10px 14px;
  cursor: pointer;
  transition: border-color .15s ease, background .15s ease;
}

.quiz-option:hover { border-color: var(--navy); }

.quiz-option.correct {
  background: #dfe8dc;
  border-color: #6f9463;
  font-weight: 600;
}

.quiz-option.incorrect {
  background: #ecdcd8;
  border-color: #b4685c;
}

.quiz-option[disabled] { cursor: default; }

.quiz-feedback {
  margin-top: 12px;
  font-size: 14.5px;
  color: var(--muted);
  min-height: 1.2em;
}

/* ---------- sources / references (collapsible) ---------- */
.sources {
  margin-top: 56px;
  padding-top: 24px;
  border-top: 2px solid var(--line);
}

.sources h2 {
  font-size: 18px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--muted);
  margin-bottom: 14px;
}

.sources-toggle {
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  user-select: none;
}

.sources-toggle .chev {
  font-size: 12px;
  color: var(--gold);
  transition: transform .15s ease;
  display: inline-block;
}

.sources.collapsed .sources-toggle .chev {
  transform: rotate(-90deg);
}

.sources-list {
  padding-left: 22px;
  font-size: 14.5px;
  color: var(--muted);
  overflow: hidden;
}

.sources.collapsed .sources-list {
  display: none;
}

.sources li { margin-bottom: 8px; }
.sources a { word-break: break-word; }

/* ---------- get-help box ---------- */
.help-box {
  background: var(--navy-dark);
  color: #ece4d4;
  border-radius: 10px;
  padding: 28px 26px;
  margin: 32px 0;
}

.help-box h2 {
  color: #fff;
  font-size: 22px;
  margin-top: 0;
}

.help-box a { color: #e0b878; }

.help-box .num {
  font-size: 26px;
  font-weight: 700;
  color: #e0b878;
}

/* ---------- reaction / was-this-helpful ---------- */
.reaction {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 40px 0 8px;
  padding: 18px 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  flex-wrap: wrap;
}

.reaction span.reaction-label {
  font-size: 14.5px;
  color: var(--muted);
  margin-right: 4px;
}

.reaction button {
  font-family: 'Source Sans 3', sans-serif;
  font-size: 14px;
  font-weight: 600;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 7px 14px;
  cursor: pointer;
  color: var(--ink);
  transition: border-color .15s ease, background .15s ease;
}

.reaction button:hover { border-color: var(--navy); }
.reaction button.picked { background: var(--navy); color: #fff; border-color: var(--navy); }

.reaction-msg {
  font-size: 14px;
  color: var(--muted);
}

/* ---------- footer ---------- */
footer.site {
  max-width: 1000px;
  margin: 40px auto 0;
  padding: 24px 24px 48px;
  color: var(--muted);
  font-size: 13.5px;
  border-top: 1px solid var(--line);
}

footer.site p { margin: 6px 0; }

@media (max-width: 640px) {
  .hero h1 { font-size: 30px; }
  .site-inner { flex-direction: column; align-items: flex-start; }
}