#radio-icon {
  position: fixed;
  right: 20px;        /* right side of screen */
  bottom: 40%;        /* vertical center-ish */
  font-size: 40px;    /* big icon */
  cursor: pointer;
  z-index: 9999;
  user-select: none;
  transition: transform 0.2s;
}

/* optional hover effect */
#radio-icon:hover {
  transform: scale(1.2);
}