#info-modal {
  display: none;
  position: fixed;  /* or absolute */
  z-index: 9999;    /* high enough to be above everything */
  top: 40%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 40%;
  height: 40%;
  background-color:gray;
  border-radius: 16px;
  padding:15;
}
#button-modal {
  position: fixed;  /* or absolute */
  z-index: 9999;    /* high enough to be above everything */
}