body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: #f4f6f9;
}

/* Header */
header {
  background: linear-gradient(to right, #667eea, #764ba2);
  color: white;
  text-align: center;
  padding: 20px;
}

/* Form */
.form-section {
  text-align: center;
  padding: 20px;
}

input {
  padding: 10px;
  margin: 8px;
  width: 200px;
  border-radius: 5px;
  border: 1px solid #ccc;
}

button {
  padding: 10px 15px;
  border: none;
  background: #667eea;
  color: white;
  border-radius: 5px;
  cursor: pointer;
}

button:hover {
  background: #5a67d8;
}

/* Book Cards */
.book-container {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}

.book {
  background: white;
  width: 250px;
  margin: 15px;
  padding: 15px;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
  transition: 0.3s;
}

.book:hover {
  transform: scale(1.05);
}

/* Category Tag */
.category {
  display: inline-block;
  background: #eee;
  padding: 5px 10px;
  border-radius: 20px;
  margin: 5px 0;
}

/* Borrow Button */
.borrowed {
  background: red;
}

.available {
  background: green;
}