.container input[type="radio"] {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}

.container {
  display: inline-block;
  position: relative;
  cursor: pointer;
  font-size: 17px;
  width: 4em;
  height: 4em;
  user-select: none;
  border: 4px solid;
  border-image-slice: 1;
  background-color: #212121;
}

label {
  font-size: 12px;
  margin-top: -6px;
  font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
  text-align: center;
  visibility: visible;
}

#topleft {
  border-image-source: linear-gradient(-45deg, #743ad5, #d53a9d);
  color: white
}

#topright {
  border-image-source: linear-gradient(45deg, #743ad5, #d53a9d);
  color: white
}

#bottomleft {
  border-image-source: linear-gradient(-135deg, #743ad5, #d53a9d);
  color: white
}

#bottomright {
  border-image-source: linear-gradient(135deg, #743ad5, #d53a9d);
  color: white
}

.selected {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

#topleft:hover {
  border-image-source: linear-gradient(-45deg, #743ad5, #d53a9d);
  background-image: linear-gradient(-45deg, #743ad5, #d53a9d);
}

#topright:hover {
  border-image-source: linear-gradient(45deg, #743ad5, #d53a9d);
  background-image: linear-gradient(45deg, #743ad5, #d53a9d);
}

#bottomleft:hover {
  border-image-source: linear-gradient(-135deg, #743ad5, #d53a9d);
  background-image: linear-gradient(-135deg, #743ad5, #d53a9d);
}

#bottomright:hover {
  border-image-source: linear-gradient(135deg, #743ad5, #d53a9d);
  background-image: linear-gradient(135deg, #743ad5, #d53a9d);
}

#topleft input[type="radio"]:checked ~ .selected {
  box-shadow: 5px 5px 25px #743ad5,
                -5px -5px 25px #d53a9d;
  border-image-slice: 1;
}

#topright input[type="radio"]:checked ~ .selected {
  box-shadow: -5px 5px 25px #743ad5,
                5px -5px 25px #d53a9d;
  border-image-slice: 1;
}

#bottomleft input[type="radio"]:checked ~ .selected {
  box-shadow: -5px 5px 25px #d53a9d,
                5px -5px 25px #743ad5;
  border-image-slice: 1;
}

#bottomright input[type="radio"]:checked ~ .selected {
  box-shadow: -5px -5px 25px #743ad5,
                5px 5px 25px #d53a9d;
  border-image-slice: 1;
}