MediaWiki:Keybinds.css

.SB-keybind-key {
  border: 1px solid #ffffff36;
  display: inline-block;
  margin: 0.25em;
  border-radius: 0.25em;
  position: relative;
  line-height: 1.3em;
  font-size: 1em;
  height: 5em;
  transition: border-color, 0.1s ease-in-out;
}
.SB-keybind-key:hover {
  filter:brightness(1.5);
}