.my-modal {
  box-shadow: 5px 5px 8px rgba(0, 0, 0, .5);
  left: 0;
  margin-left: auto;
  margin-right: auto;
  max-width: 550px;
  overflow: hidden;
  position: fixed;
  right: 0;
  top: 0;
  width: calc(100% - 30px);
  z-index: 10001;
}

.my-modal .header {
  position: relative;
}

.my-modal .x {
  color: white;
  cursor: pointer;
  font-size: 1.4em;
  position: absolute;
  right: 10px;
  top: 0;
}

#my-modal-backdrop {
  background: black;
  height: 100%;
  left: 0;
  opacity: 0.2;
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 10000;
}