:root {
  --md-primary-fg-color: #b71c1c;
  --md-primary-fg-color--light: #ef5350;
  --md-primary-fg-color--dark: #7f0000;
  --md-accent-fg-color: #d84315;
}

[data-md-color-scheme="slate"] {
  --md-hue: 4;
  --md-default-bg-color: #1b0808;
  --md-default-bg-color--light: #2d1010;
}

.book-hero {
  background:
    radial-gradient(circle at top right, rgb(255 255 255 / 18%), transparent 38%),
    linear-gradient(135deg, #7f0000 0%, #c62828 58%, #ff8a80 100%);
  border-radius: 1.2rem;
  box-shadow: 0 1rem 2.4rem rgb(127 0 0 / 20%);
  color: #fff;
  margin: 1rem 0 2rem;
  overflow: hidden;
  padding: clamp(2rem, 7vw, 4.5rem);
}

.book-hero h1 {
  color: #fff;
  font-size: clamp(2.2rem, 6vw, 4.2rem);
  letter-spacing: -0.04em;
  line-height: 1.02;
  margin: 0 0 0.7rem;
}

.book-hero p {
  font-size: 1.15rem;
  margin-bottom: 0;
  max-width: 36rem;
}

.chapter-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
  margin: 1.5rem 0;
}

.chapter-card {
  border: 1px solid color-mix(in srgb, var(--md-primary-fg-color) 32%, transparent);
  border-radius: 0.85rem;
  color: inherit;
  padding: 1rem 1.1rem;
  transition: border-color 160ms ease, transform 160ms ease;
}

.chapter-card:hover {
  border-color: var(--md-accent-fg-color);
  transform: translateY(-2px);
}

.chapter-card strong {
  color: var(--md-primary-fg-color);
  display: block;
  margin-bottom: 0.3rem;
}