.alert-error {
  background:#ffe6e6;
  border:2px solid #c00;
  color:#600;
  border-radius:6px;
  font-size: 16px;
}
.alert-error strong {
  display:block;
  margin-bottom:6px;
}

.book-form .checkbox-field {
  margin-top: 15px;
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 18px;
}

.book-form .checkbox-field input[type="checkbox"] {
  margin-top: 4px;
  accent-color: var(--theme-color, #0f6);
}

.book-form .captcha-field {
  margin-top: 15px;
  font-size: 18px;
}

.book-form .captcha-field input {
  width: 100%;
  margin-top: 6px;
}

.book-form .alert {
  border-radius: 4px;
  padding: 10px 15px;
  margin-bottom: 15px;
}

.alert-error {
  background: #fee;
  border: 1px solid #f99;
  color: #900;
}

.alert-success {
  background: #efe;
  border: 1px solid #9c9;
  color: #060;
}

.margin-center {
        margin-left: auto;
        margin-right: auto;
}