:root {
  color-scheme: light;
  --navy: #232d4b;
  --orange: #e57200;
  --link: #4a6e9d;
  --ink: #263044;
  --muted: #586174;
  --border: #d9dee8;
  --paper: #ffffff;
  --wash: #f6f8fb;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--wash);
}

a {
  color: var(--link);
}

.skip-link {
  position: fixed;
  z-index: 20;
  top: 0.5rem;
  left: 0.5rem;
  padding: 0.55rem 0.75rem;
  border-radius: 0.35rem;
  color: white;
  background: var(--navy);
  transform: translateY(-180%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  border-bottom: 1px solid var(--border);
  background: rgb(255 255 255 / 0.94);
}

.site-header-inner,
.download-landing,
.site-footer-inner {
  width: min(74rem, calc(100% - 2.4rem));
  margin-inline: auto;
}

.site-header-inner {
  display: flex;
  min-height: 4.15rem;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.book-home {
  color: var(--navy);
  font-weight: 800;
  text-decoration: none;
}

.book-home:hover,
.book-home:focus-visible,
.read-online:hover,
.read-online:focus-visible {
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

.read-online {
  font-weight: 700;
  text-decoration: none;
}

.download-landing {
  padding: clamp(1.5rem, 4vw, 3rem) 0 3.5rem;
}

.download-grid {
  display: grid;
  grid-template-columns: minmax(16rem, 0.82fr) minmax(22rem, 1.18fr);
  gap: clamp(2rem, 5vw, 4.8rem);
  align-items: start;
}

.download-cover {
  position: sticky;
  top: 1.5rem;
  margin: 0;
}

.download-cover img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 0.42rem;
  box-shadow: 0 1.4rem 3.2rem rgb(5 14 31 / 0.22);
}

.download-cover figcaption {
  margin-top: 0.75rem;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.45;
  text-align: center;
}

.download-offer {
  padding-top: 0.35rem;
}

h2 {
  color: var(--navy);
}

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

.download-price-summary {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.8rem;
  margin: 1.25rem 0 1.4rem;
}

.download-price-summary > div {
  padding: 0.85rem 1rem;
  border: 1px solid var(--border);
  border-radius: 0.55rem;
  background: var(--paper);
}

.download-price-summary span {
  display: block;
  margin-bottom: 0.18rem;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 850;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.download-price-summary strong {
  color: var(--navy);
  font-size: 1.42rem;
}

.price-support-link {
  color: var(--link);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.14em;
}

.download-action {
  display: inline-flex;
  min-height: 2.9rem;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 0.95rem;
  border: 2px solid var(--navy);
  border-radius: 0.42rem;
  color: white;
  background: var(--navy);
  font-weight: 850;
  line-height: 1.25;
  text-align: center;
  text-decoration: none;
}

.download-action:hover,
.download-action:focus-visible {
  color: white;
  background: #161f36;
}

.download-action:focus-visible {
  outline: 3px solid var(--orange);
  outline-offset: 3px;
}

.free-downloads {
  margin-top: 1.45rem;
  padding-top: 1.35rem;
  border-top: 1px solid var(--border);
}

.free-downloads h2 {
  margin: 0 0 0.35rem;
  font-size: 1.42rem;
}

.free-downloads > p {
  margin: 0 0 0.85rem;
  color: var(--muted);
}

.download-editions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
}

.download-edition {
  align-items: flex-start;
  flex-direction: column;
}

.download-edition span {
  font-size: 0.78rem;
  font-weight: 550;
  opacity: 0.82;
}

.download-license-note {
  margin: 1rem 0 0;
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.5;
}

.site-footer {
  border-top: 1px solid var(--border);
  background: white;
}

.site-footer-inner {
  padding: 1.25rem 0;
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.5;
}

@media (max-width: 760px) {
  .site-header-inner,
  .download-landing,
  .site-footer-inner {
    width: min(100% - 1.4rem, 38rem);
  }

  .site-header-inner {
    min-height: 3.75rem;
  }

  .book-home {
    max-width: 13rem;
    line-height: 1.25;
  }

  .download-grid {
    grid-template-columns: 1fr;
    gap: 1.8rem;
  }

  .download-cover {
    position: static;
    width: min(72vw, 17rem);
    margin-inline: auto;
  }

  .download-editions {
    grid-template-columns: 1fr;
  }

  .download-action {
    width: 100%;
  }
}

@media (max-width: 420px) {
  .download-price-summary {
    grid-template-columns: 1fr;
  }
}

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

}