#modal {
  width: 80%;
  max-width: 800px;
  margin: 0 auto;
  font-size: 1.3em;
  text-align: left;  
  line-height: 1.6; 
  position: fixed;
  left: calc(50% - 225px);
  top: 20px !important;
  height: 90%;
  max-height: 530px;
  background-color: #252525;
}
#modal iframe {
  width: 100%;
  height: 100%;
}