body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f4f4f4;
}

header {
  background-color:#004d40;
  color: white;
  padding: 1rem;
  text-align: center;
}
nav a {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  background-color: #eee;
  padding: 1rem;
}

nav a button:hover {
  background-color: #ccc;
}

nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  background-color: #004d40;
  padding: 1rem;
}

nav button {
  margin: 0.5rem;
  padding: 0.6rem 1rem;
  border: none;
  background-color: #ddd;
  cursor: pointer;
  border-radius: 4px;
  font-size: 1rem;
}

nav button:hover {
  background-color: #ccc;
}

#ebook-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  padding: 2rem;
}

.ebook-card {
  background-color: white;
  border: 1px solid #ddd;
  border-radius: 6px;
  margin: 1rem;
  padding: 1.2rem;
  width: 260px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
  transition: transform 0.2s;
}

.ebook-card:hover {
  transform: scale(1.02);
}

.ebook-card h3 {
  margin-top: 0;
}

.ebook-card p {
  font-size: 0.9rem;
  color: #555;
  margin: 0.3rem 0;
}

.btn-pdf {
  display: inline-block;
  margin-top: 0.8rem;
  padding: 0.5rem 0.9rem;
  background-color: #0066cc;
  color: white;
  text-decoration: none;
  border-radius: 4px;
  font-size: 0.9rem;
}

.btn-pdf:hover {
  background-color: #004c99;
}
footer {
  background-color: #004d40;
  color: white;
  text-align: center;
  padding: 15px;
  font-size: 2em;
  margin-top: 30px;
}