.popup {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 9999;
}

.popup-content {
  background-color: #fff;
  width: 50%;
  max-width: 400px;
  margin: 100px auto;
  padding: 20px;
  border-radius: 5px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
}

.close {
  position: absolute;
  top: 10px;
  right: 10px;
  cursor: pointer;
}