body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  line-height: 1.6;
  background-color: #f9f9f9;
  color: #333;
}

header {
  background-color: #ffffff;
  text-align: center;
  padding: 20px 10px;
  border-bottom: 1px solid #ddd;
}

.logo {
  width: 180px;
  height: auto;
  margin-bottom: 10px;
}

h1 {
  margin: 0;
  font-size: 2.2em;
}

.sottotitolo {
  font-size: 1em;
  color: #666;
  margin-top: 5px;
}

nav {
  margin-top: 15px;
}

nav a {
  text-decoration: none;
  color: #0066cc;
  margin: 0 10px;
  font-weight: bold;
}

nav a.active {
  color: #333;
  text-decoration: underline;
}

main {
  max-width: 800px;
  margin: 30px auto;
  padding: 0 20px;
}

ul.libri {
  list-style: none;
  padding: 0;
}

ul.libri li {
  margin-bottom: 15px;
  padding-left: 1em;
  text-indent: -1em;
}

footer {
  text-align: center;
  padding: 20px;
  font-size: 0.9em;
  background-color: #fff;
  border-top: 1px solid #ddd;
}