* { box-sizing: border-box; }
body {
  font-family: -apple-system, "Hiragino Sans", "Yu Gothic", sans-serif;
  margin: 0;
  background: #f5f5f5;
  color: #222;
}
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 1.5rem;
  background: #2c3e50;
  color: #fff;
}
.topbar .brand {
  color: #fff;
  text-decoration: none;
  font-weight: bold;
  font-size: 1.1rem;
}
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 1.5rem;
}
.login-page {
  max-width: 360px;
  margin-top: 4rem;
  text-align: center;
}
.card {
  background: #fff;
  border-radius: 8px;
  padding: 1.5rem;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}
.card label {
  display: block;
  margin-top: 0.75rem;
  font-weight: bold;
}
.card input,
.card select,
.card textarea {
  width: 100%;
  padding: 0.5rem;
  margin-top: 0.25rem;
  border: 1px solid #ccc;
  border-radius: 4px;
  font-size: 1rem;
}
.card button {
  margin-top: 1.25rem;
  padding: 0.6rem 1.2rem;
  background: #2c3e50;
  color: #fff;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}
.page-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.button {
  background: #2c3e50;
  color: #fff;
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 4px;
}
.search-form {
  display: flex;
  gap: 0.5rem;
  margin: 1rem 0;
}
.search-form input {
  flex: 1;
  padding: 0.5rem;
  border: 1px solid #ccc;
  border-radius: 4px;
}
.book-table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
}
.book-table th,
.book-table td {
  padding: 0.6rem;
  border-bottom: 1px solid #eee;
  text-align: left;
}
.actions {
  display: flex;
  gap: 0.75rem;
  align-items: center;
}
.link-button {
  background: none;
  border: none;
  color: #c0392b;
  cursor: pointer;
  padding: 0;
  font-size: 1rem;
  text-decoration: underline;
}
.pagination {
  display: flex;
  gap: 1rem;
  align-items: center;
  justify-content: center;
  margin-top: 1.5rem;
}
.form-actions {
  margin-top: 1.5rem;
  display: flex;
  gap: 1rem;
  align-items: center;
}
.error {
  color: #c0392b;
  font-weight: bold;
}
.result-count {
  color: #666;
}
.isbn-row {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}
.isbn-row input {
  flex: 1;
}
.isbn-row button {
  margin-top: 0.25rem;
  padding: 0.5rem 1rem;
  background: #2c3e50;
  color: #fff;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  white-space: nowrap;
}
.lookup-message {
  margin: 0.25rem 0 0;
  font-size: 0.85rem;
  color: #666;
}