:root {
  --hero-bg: #050608;
  --text-on-dark: #f4f4f4;
  --accent: #a84b2a;
  --accent-soft: #d3b66a;
  --section-light: #ece6da;
  --section-white: #f7f6f2;
  --body-text: #1d1d1d;
  --card-bg: #d7d2c7;
  --card-border: #8f8a82;
  --footer-bg: #0a0a0a;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, sans-serif;
  color: var(--body-text);
  line-height: 1.6;
  background: var(--section-white);
}

.container {
  width: min(1100px, 92%);
  margin: 0 auto;
}

.hero {
  background-image: linear-gradient(180deg, rgba(0, 0, 0, 0.55) 0%, rgba(16, 23, 34, 0.65) 100%), url("img/sfondo.jpg");
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
  color: var(--text-on-dark);
  text-align: center;
  padding-bottom: 2rem;
  border-bottom: 4px solid var(--accent);
}

.hero-nav {
  padding: 1rem 0;
  font-size: 1.05rem;
  letter-spacing: 0.04em;
}

.hero-content {
  padding: 2rem 0 1rem;
}

.hero h1 {
  margin: 0;
  font-size: clamp(1.9rem, 4vw, 3rem);
}

.hero p {
  margin-top: 0.75rem;
  font-size: 1.1rem;
  color: var(--accent-soft);
}

section {
  padding: 4rem 0;
}

.section-light {
  background: var(--section-light);
}

.section-white {
  background: var(--section-white);
}

.intro-grid {
  display: grid;
  grid-template-columns: 1fr 1.3fr;
  gap: 2rem;
  align-items: center;
}

.cover-wrap {
  text-align: center;
}

.book-cover {
  width: 100%;
  max-width: 280px;
  height: auto;
  box-shadow: 0 20px 35px rgba(0, 0, 0, 0.35);
  border-radius: 6px;
}

.book-info h2 {
  margin-top: 0;
  line-height: 1.25;
  color: #121212;
}

.author-line {
  font-weight: 700;
  margin: 0.35rem 0 1rem;
  color: #3e3e3e;
}

.book-info ul {
  list-style: none;
  padding-left: 0;
  margin: 0 0 1.5rem;
}

.cta-btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  border-radius: 10px;
  padding: 0.85rem 1.4rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.cta-btn:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.prose {
  max-width: 900px;
}

.topics-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.topic-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 1rem;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.topic-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.12);
}

.authors-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem;
}

.author-card {
  border: 1px solid #c8c2b6;
  border-radius: 10px;
  padding: 1.25rem;
  background: #fdfcf9;
}

.final-cta {
  text-align: center;
}

.cta-center p {
  font-size: 1.05rem;
  margin-top: 0;
}

footer {
  background: var(--footer-bg);
  color: #e7e7e7;
  text-align: center;
  padding: 1.5rem 0;
  border-top: 3px solid var(--accent-soft);
}

.footer-content p {
  margin: 0.3rem 0;
}

@media (min-width: 601px) and (max-width: 1024px) {
  .intro-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .topics-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 600px) {
  section {
    padding: 3rem 0;
  }

  .intro-grid,
  .topics-grid,
  .authors-grid {
    grid-template-columns: 1fr;
  }

  .book-cover {
    max-width: 100%;
  }
}