:root {
  color-scheme: light;
  --ink: #21313a;
  --muted: #5c6970;
  --paper: #fffaf0;
  --panel: #ffffff;
  --line: #d8ddd7;
  --teal: #2f8891;
  --red: #e9564f;
  --gold: #f6c85f;
  --green: #4f9d69;
  --shadow: 0 18px 50px rgba(33, 49, 58, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
}

a {
  color: inherit;
}

button {
  font: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 14px clamp(18px, 4vw, 56px);
  border-bottom: 1px solid rgba(33, 49, 58, 0.12);
  background: rgba(255, 250, 240, 0.92);
  backdrop-filter: blur(14px);
}

.brand,
.main-nav,
.site-footer nav {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand {
  text-decoration: none;
  font-weight: 800;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
  font-size: 0.8rem;
}

.main-nav a,
.site-footer a {
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 650;
  text-decoration: none;
}

.main-nav a:hover,
.site-footer a:hover {
  color: var(--ink);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(340px, 1fr);
  align-items: center;
  gap: clamp(28px, 5vw, 80px);
  min-height: calc(100vh - 84px);
  padding: clamp(44px, 7vw, 92px) clamp(18px, 4vw, 56px) 36px;
}

.hero h1 {
  max-width: 820px;
  margin: 0;
  font-size: clamp(4rem, 9vw, 8.5rem);
  line-height: 0.86;
  letter-spacing: 0;
}

.hero p:not(.eyebrow) {
  max-width: 620px;
  color: var(--muted);
  font-size: 1.15rem;
}

.hero img {
  width: 100%;
  min-width: 0;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--teal);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.primary-link,
.primary-button,
.ghost-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 16px;
  border: 1px solid var(--ink);
  border-radius: 8px;
  cursor: pointer;
  font-weight: 800;
  text-decoration: none;
}

.primary-link,
.primary-button {
  background: var(--ink);
  color: #fff;
}

.ghost-button {
  background: #fff;
  color: var(--ink);
}

.primary-button:disabled {
  cursor: not-allowed;
  opacity: 0.5;
}

.section {
  padding: clamp(52px, 7vw, 96px) clamp(18px, 4vw, 56px);
}

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 22px;
}

.section h2 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 4rem);
  line-height: 1;
  letter-spacing: 0;
}

.quiz-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.quiz-tile {
  display: flex;
  min-height: 172px;
  width: 100%;
  flex-direction: column;
  justify-content: space-between;
  gap: 18px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  color: inherit;
  cursor: pointer;
  box-shadow: 0 10px 28px rgba(33, 49, 58, 0.07);
  text-align: left;
  transition: border-color 160ms ease, box-shadow 160ms ease, transform 160ms ease;
}

.quiz-tile:hover,
.quiz-tile:focus-visible {
  border-color: var(--teal);
  box-shadow: 0 16px 34px rgba(33, 49, 58, 0.12);
  transform: translateY(-2px);
}

.quiz-tile:focus-visible {
  outline: 3px solid rgba(47, 136, 145, 0.28);
  outline-offset: 2px;
}

.quiz-tile h3 {
  margin: 0 0 8px;
  font-size: 1.15rem;
}

.quiz-tile p {
  margin: 0;
  color: var(--muted);
}

.quiz-preview {
  display: block;
  min-height: 48px;
  color: var(--ink);
  font-size: 0.95rem;
  font-weight: 750;
}

.quiz-cta {
  display: inline-flex;
  align-items: center;
  align-self: flex-start;
  min-height: 38px;
  padding: 8px 12px;
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
  font-size: 0.92rem;
  font-weight: 800;
}

.topic-library {
  display: grid;
  grid-template-columns: minmax(240px, 0.45fr) minmax(280px, 1fr);
  gap: clamp(24px, 5vw, 68px);
  padding-top: 0;
}

.topic-library ul {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.topic-library a {
  display: flex;
  min-height: 44px;
  align-items: center;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.7);
  color: var(--ink);
  font-weight: 750;
  text-decoration: none;
}

.topic-library a:hover,
.topic-library a:focus-visible {
  border-color: var(--teal);
  outline: 3px solid rgba(47, 136, 145, 0.2);
  outline-offset: 2px;
}

.quiz-panel {
  padding: 30px clamp(18px, 4vw, 56px) 72px;
}

.quiz-shell {
  display: grid;
  grid-template-columns: minmax(240px, 320px) minmax(0, 1fr);
  gap: 18px;
}

.quiz-sidebar,
.question-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 10px 28px rgba(33, 49, 58, 0.07);
}

.quiz-sidebar {
  align-self: start;
  padding: 18px;
}

.quiz-sidebar h2 {
  margin: 18px 0 8px;
  font-size: 1.8rem;
  line-height: 1.05;
}

.quiz-sidebar p {
  color: var(--muted);
}

.progress-card {
  display: grid;
  gap: 10px;
  margin-top: 22px;
}

.progress-track {
  height: 10px;
  overflow: hidden;
  border-radius: 999px;
  background: #e9ece8;
}

.progress-track span {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: var(--teal);
  transition: width 180ms ease;
}

.question-card {
  min-height: 440px;
  padding: clamp(20px, 4vw, 42px);
}

.question-card h3 {
  min-height: 96px;
  margin: 0 0 24px;
  font-size: clamp(1.7rem, 3vw, 2.6rem);
  line-height: 1.12;
  letter-spacing: 0;
}

.answer-options {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.answer-option {
  min-height: 66px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  cursor: pointer;
  text-align: left;
  font-weight: 750;
}

.answer-option:hover:not(:disabled) {
  border-color: var(--teal);
}

.answer-option.correct {
  border-color: var(--green);
  background: rgba(79, 157, 105, 0.13);
}

.answer-option.incorrect {
  border-color: var(--red);
  background: rgba(233, 86, 79, 0.12);
}

.answer-option:disabled {
  cursor: default;
}

.fact-text {
  min-height: 58px;
  margin: 20px 0;
  color: var(--muted);
  font-weight: 650;
}

.quiz-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.info-section {
  display: grid;
  grid-template-columns: minmax(240px, 0.7fr) minmax(280px, 1fr);
  gap: clamp(24px, 5vw, 68px);
  border-top: 1px solid rgba(33, 49, 58, 0.12);
}

.info-section p:last-child {
  max-width: 760px;
  margin: 0;
  color: var(--muted);
  font-size: 1.1rem;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 24px clamp(18px, 4vw, 56px);
  border-top: 1px solid rgba(33, 49, 58, 0.12);
  color: var(--muted);
}

.legal-page {
  max-width: 920px;
  margin: 0 auto;
  padding: clamp(36px, 7vw, 84px) 18px;
}

.legal-page h1 {
  margin: 0 0 18px;
  font-size: clamp(2.4rem, 6vw, 5rem);
  line-height: 0.95;
  letter-spacing: 0;
}

.legal-page h2 {
  margin-top: 34px;
}

.legal-page p,
.legal-page li {
  color: var(--muted);
}

@media (max-width: 820px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .main-nav {
    flex-wrap: wrap;
  }

  .hero,
  .quiz-shell,
  .topic-library,
  .info-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .hero h1 {
    font-size: clamp(3.4rem, 18vw, 6rem);
  }

  .answer-options {
    grid-template-columns: 1fr;
  }
}