#modalOverlay {
  width: 100%;
  height: 100%;
  z-index: 2; /* places the modal overlay between the main page and the modal dialog*/
  background-color: #000;
  opacity: 0.5;
  position: fixed;
  top: 0;
  left: 0;
  display: none;
  margin: 0;
  padding: 0;
}

#modal {
  width: 50%;
  margin-left: auto;
  margin-right: auto;
  padding: 20px;
  border: 3px #fff solid;
  background-color: #16A085;
  color: #fff;
  z-index: 3; /* places the modal dialog on top of everything else */
  position: fixed;
  top: 25%;
  left: 25%;
  display: none;
}

#modal h1 { text-align: center; }

.modalCloseButton {
  float: right;
  position: absolute;
  top: 10px;
  left: 92%;
  height: 25px;
  border: 0;
  background-color: #16A085;
}

.modalCloseButton img { border: 0; }

.screen-reader-offscreen {
  position: absolute;
  left: -999px;
  width: 1px;
  height: 1px;
  top: auto;
}