body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: #f8f9fa;
  color: #333;
}

header {
  background-color: #0d47a1;
  color: white;
  text-align: center;
  padding: 1rem;
  font-size: 1.5rem;
}

nav {
  background-color: #1976d2;
}

nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  margin: 0;
  padding: 0;
}

nav li {
  margin: 0.5rem 1rem;
}

nav a {
  color: white;
  text-decoration: none;
  font-weight: bold;
}

main {
  padding: 1.5rem;
}

section {
  margin-bottom: 2rem;
}

.book-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

.book {
  background: white;
  border-radius: 8px;
  padding: 1rem;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

form {
  display: flex;
  flex-direction: column;
  max-width: 400px;
  gap: 0.8rem;
}

input, textarea {
  padding: 0.6rem;
  font-size: 1rem;
  border: 1px solid #ccc;
  border-radius: 4px;
}

button {
  background-color: #0d47a1;
  color: white;
  padding: 0.7rem;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

footer {
  text-align: center;
  background: #0d47a1;
  color: white;
  padding: 1rem;
  margin-top: 2rem;
}