.isbn-wrap {
  width: 100%;
  padding: 4px 0 24px;
  box-sizing: border-box;
}

.isbn-form {
  width: 100%;
}

.isbn-field {
  margin-bottom: 12px;
}

.isbn-input {
  display: block;
  width: 100%;
  max-width: 100%;
  padding: 10px 14px;
  border: 1px solid #d1d5db;
  border-radius: 4px;
  font-size: 15px;
  line-height: 1.5;
  color: #111827;
  background: #fff;
  box-sizing: border-box;
  letter-spacing: 0.02em;
}

.isbn-input:focus {
  outline: none;
  border-color: #3b82f6;
  box-shadow: 0 0 0 1px rgba(59, 130, 246, 0.15);
}

.isbn-actions {
  margin-bottom: 12px;
}

.isbn-btn {
  display: inline-block;
  padding: 9px 20px;
  border: none;
  border-radius: 4px;
  font-size: 14px;
  font-weight: 500;
  line-height: 1.5;
  cursor: pointer;
  transition: background-color 0.15s ease;
}

.isbn-btn-primary {
  background: #10b981;
  color: #fff;
}

.isbn-btn-primary:hover {
  background: #059669;
}

.isbn-btn-secondary {
  background: #e5e7eb;
  color: #374151;
  margin: 0 6px;
}

.isbn-btn-secondary:hover {
  background: #d1d5db;
}

.isbn-tips {
  margin: 0 0 12px;
  padding: 10px 12px;
  font-size: 13px;
  line-height: 1.5;
  border-radius: 4px;
}

.isbn-tips.is-error {
  background: #ffd5d5;
  color: #991b1b;
}

.isbn-result {
  margin-top: 8px;
  padding: 20px 16px;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  background: #fff;
  text-align: center;
}

.isbn-label {
  font: bold 17px Courier, "Courier New", monospace;
  color: #111;
  margin-bottom: 8px;
  letter-spacing: 0.5px;
}

.isbn-barcode-box {
  display: flex;
  justify-content: center;
  align-items: center;
  overflow-x: auto;
  max-width: 100%;
}

.isbn-barcode-box svg {
  max-width: 100%;
  height: auto;
}

.isbn-download {
  margin-top: 16px;
}

.isbn-note {
  margin: 14px 0 0;
  font-size: 13px;
  color: #6b7280;
  line-height: 1.6;
}

.isbn-intro {
  margin-top: 28px;
  padding: 20px;
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  border-radius: 6px;
}

.isbn-intro h2 {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 600;
  color: #111827;
}

.isbn-intro h2 + p,
.isbn-intro p + p {
  margin-top: 0;
}

.isbn-intro h2:not(:first-child) {
  margin-top: 22px;
}

.isbn-intro h3 {
  margin: 14px 0 6px;
  font-size: 15px;
  font-weight: 600;
  color: #1f2937;
}

.isbn-intro p,
.isbn-intro li {
  margin: 0 0 10px;
  font-size: 14px;
  line-height: 1.7;
  color: #4b5563;
}

.isbn-intro ol {
  margin: 0;
  padding-left: 1.35em;
}

.isbn-intro ol li {
  margin-bottom: 6px;
}

@media (max-width: 640px) {
  .isbn-download .isbn-btn {
    display: block;
    width: 100%;
    margin: 0 0 8px;
  }
}