.modal-backdrop[hidden] { display: none; }
.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  background: rgba(0, 0, 0, .55);
}
.fancy-box {
  position: relative;
  display: block;
  max-width: 100%;
  max-height: calc(100vh - 40px);
  overflow: auto;
}
.modal-close {
  position: absolute;
  top: 5px;
  right: 10px;
  border: 0;
  background: transparent;
  color: #333;
  font-size: 28px;
  line-height: 1;
  cursor: pointer;
}
@media (max-width: 520px) {
  .fancy-box { width: 450px; padding: 28px 20px 20px; }
}