/* Base styles */
body {
  font-family: "Segoe UI", sans-serif;
  margin: 0;
  background: #f4f6f8;
  color: #333;
}

/* Header with blue background */
header {
  background: #0a66c2;
  color: white;
  padding: 40px 20px;
  text-align: center;
}

/* Sub-title styling */
header p {
  margin-top: 10px;
  font-size: 16px;
  color: #e5f2ff;
}

/* Main menu styled as tabs */
.main-menu {
  display: flex;
  justify-content: center;
  background: #e0e7ef;
  border-bottom: 2px solid #0a66c2;
}

.main-menu a {
  padding: 14px 20px;
  font-weight: bold;
  color: #0a66c2;
  font-size: 16px;
  text-decoration: none;
}

.main-menu a:hover {
  background: #f4f7fb;
}

/* Content container */
.container {
  max-width: 1000px;
  margin: 30px auto;
  padding: 0 20px;
}

/* Card styling */
.card {
  background: white;
  padding: 20px;
  border-radius: 8px;
  margin-bottom: 20px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.05);
}

h2 {
  color: #0a66c2;
}

/* Links list styling */
.link-list a {
  display: block;
  margin: 6px 0;
  color: #0a66c2;
  text-decoration: none;
}

/* Gallery of books styling */
.livros-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 20px;
  margin-top: 30px;
}

.livro-card {
  background: #ffffff;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 3px 10px rgba(0,0,0,0.08);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  text-align: center;
}

.livro-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 6px 18px rgba(0,0,0,0.12);
}

.livro-card img {
  width: 100%;
  height: 240px;
  object-fit: cover;
}

.livro-card h3 {
  font-size: 1rem;
  margin: 10px 0 0;
  color: #0a66c2;
}

/* Footer styling */
footer {
  text-align: center;
  padding: 20px;
  font-size: 13px;
  color: #777;
}