:root {
  color-scheme: light;
  --ink: #172019;
  --muted: #5c675f;
  --paper: #f5f1e8;
  --paper-deep: #e7dfcf;
  --accent: #185b43;
  --accent-dark: #0d3c2c;
  --line: rgba(23, 32, 25, 0.16);
  --white: #fffdf8;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 80% 8%, rgba(24, 91, 67, 0.12), transparent 25rem),
    var(--paper);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", "Noto Sans CJK SC", sans-serif;
  line-height: 1.6;
}

main,
footer {
  width: min(1120px, calc(100% - 40px));
  margin-inline: auto;
}

.hero {
  min-height: 82vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 90px 0 72px;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--accent);
  font-size: 0.77rem;
  font-weight: 750;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  text-wrap: pretty;
}

h1,
h2 {
  font-family: Georgia, "Noto Serif CJK SC", serif;
  font-weight: 500;
  line-height: 1.04;
  letter-spacing: -0.035em;
}

h1 {
  max-width: 900px;
  margin: 0;
  font-size: clamp(3.2rem, 8.6vw, 7.4rem);
}

.subtitle {
  margin: 26px 0 0;
  color: var(--accent);
  font-family: Georgia, "Noto Serif CJK SC", serif;
  font-size: clamp(1.35rem, 2.5vw, 2rem);
  font-style: italic;
}

.summary {
  max-width: 720px;
  margin: 34px 0 0;
  color: var(--muted);
  font-size: 1.05rem;
}

.downloads {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 38px;
}

.button {
  min-width: 246px;
  padding: 16px 19px;
  border: 1px solid var(--accent);
  border-radius: 5px;
  text-decoration: none;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.button span,
.button small {
  display: block;
}

.button span {
  font-weight: 720;
}

.button small {
  margin-top: 2px;
  font-size: 0.76rem;
  opacity: 0.72;
}

.button-primary {
  color: var(--white);
  background: var(--accent);
}

.button-secondary {
  color: var(--accent-dark);
  background: rgba(255, 253, 248, 0.44);
}

.button:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 24px rgba(23, 32, 25, 0.12);
}

.button-primary:hover {
  background: var(--accent-dark);
}

.button:focus-visible,
.source-link:focus-visible {
  outline: 3px solid rgba(24, 91, 67, 0.35);
  outline-offset: 4px;
}

.source-link {
  align-self: flex-start;
  margin-top: 26px;
  color: var(--ink);
  font-size: 0.9rem;
  text-underline-offset: 4px;
}

.contents {
  padding: 96px 0 110px;
  border-top: 1px solid var(--line);
}

.section-heading {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 32px;
  align-items: start;
  margin-bottom: 56px;
}

.section-heading h2 {
  max-width: 730px;
  margin: 0;
  font-size: clamp(2.2rem, 5vw, 4.4rem);
}

.part-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 44px;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.part-grid li {
  display: grid;
  grid-template-columns: 46px 1fr;
  gap: 18px;
  padding: 27px 0 29px;
  border-bottom: 1px solid var(--line);
}

.part-number {
  color: var(--accent);
  font-family: Georgia, serif;
  font-size: 1.3rem;
}

.part-grid h3 {
  margin: 0;
  font-family: Georgia, "Noto Serif CJK SC", serif;
  font-size: 1.22rem;
  font-weight: 600;
}

.part-grid p {
  margin: 7px 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 28px 0 38px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.8rem;
}

footer p {
  margin: 0;
}

@media (max-width: 700px) {
  main,
  footer {
    width: min(100% - 28px, 1120px);
  }

  .hero {
    min-height: auto;
    padding: 70px 0 60px;
  }

  h1 {
    font-size: clamp(2.75rem, 14vw, 4.5rem);
  }

  .downloads {
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .contents {
    padding: 70px 0 76px;
  }

  .section-heading,
  .part-grid {
    grid-template-columns: 1fr;
  }

  .section-heading {
    gap: 6px;
    margin-bottom: 38px;
  }

  .part-grid {
    gap: 0;
  }

  footer {
    flex-direction: column;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .button {
    transition: none;
  }
}