/* Import a modern Google Font */
@import url('https://fonts.googleapis.com/css2?family=Open+Sans&display=swap');

body {
  font-family: 'Open Sans', Arial, sans-serif;
  background-color: #fafafa;
  color: #2c3e50;
  margin: 0;
  padding: 20px;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

h1 {
  text-align: center;
  font-weight: 700;
  font-size: 24px;
  line-height: 1.4;
  margin-top: 20px;
  margin-bottom: 30px;
  color: #34495e;
  position: relative;
}

h1::after {
  content: "";
  display: block;
  width: 60px;
  height: 3px;
  background: #3498db;
  margin: 12px auto 0 auto;
  border-radius: 2px;
}

/* Common input styles (search & select) */
input[type="text"],
select {
  width: 100%;
  max-width: 500px;
  padding: 12px 15px;
  font-size: 15px;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  border: 1px solid #ccc;
  border-radius: 6px;
  margin: 0 auto 20px auto;
  display: block;
  box-sizing: border-box;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

input[type="text"]:focus,
select:focus {
  outline: none;
  border-color: #2980b9;
  box-shadow: 0 0 6px #2980b9aa;
}

/* Book list */
#book-list {
  list-style-type: none;
  padding: 0;
  margin: 0 auto;
  max-width: 600px;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

#book-list li {
  padding: 15px 20px;
  border-bottom: 1px solid #eee;
  font-size: 18px;
  transition: background-color 0.3s ease;
  cursor: default;
}

#book-list li:last-child {
  border-bottom: none;
}

#book-list li:hover {
  background-color: #f0f8ff;
}

/* Footer */
footer {
  margin-top: 40px;
  text-align: center;
  color: #aaa;
  font-size: 14px;
}

/* Responsive tweaks */
@media (max-width: 480px) {
  body {
    padding: 15px 10px;
  }

  h1 {
    font-size: 20px;
  }

  input[type="text"],
  select {
    font-size: 14px;
  }

  #book-list li {
    font-size: 16px;
    padding: 12px 15px;
  }
}