body{
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 20px;
}
.title{
    text-align: center;
}
.container {
    max-width: 600px;
    margin: auto;
    padding: 20px;
    background-color: #fff;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    border-radius: 10px;
}
form {
  margin-bottom: 30px;
}
form input {
  box-sizing: border-box;
  font-size: 1.1em;
  margin: 8px 0; 
  width: 100%;   
  padding: 10px;
}
form button {
  background: #4CAF50;
  color: white;
  border: none;
  cursor: pointer;
  font-size: 1.2em;
  padding: 15px;
  margin-top: 10px;
  border-radius: 5px;
  width: 100%;
  transition: background 0.2s;
}
form button:hover {
  background: #388e3c;
}
#bookList {
  margin-top: 20px;
  padding: 0;
  list-style: none;
}
li {
  background: #eee;
  margin: 10px 0;
  padding: 15px;
  border-radius: 5px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.book-details {
  background: #fafafa;
  border: 1px solid #ddd;
  border-radius: 8px;
  padding: 20px;
  margin-top: 20px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.07);
  display: none;
}
.book-details.active {
  display: block;
}