body {
  margin: 0;
  background: #eee;
  color: #555;
  font-family: sans-serif;
  text-align: center;
}
input {
  position: absolute;
  top: 0;
  left: 0;
  min-width: 100%;
  min-height: 100%;
  opacity: 0;
  cursor: pointer;
}
a, div, canvas {
  display: block;
  width: 256px;
  margin: 1em auto;
}
a, div {
  position: relative;
  padding: 5px;
  color: inherit;
  border: solid;
  text-decoration: none;
  user-select: none;
  -webkit-user-select: none;
}
a:active, div:active { background: #ccc }
a:not([href]) { display: none }