body {
  background: url("./drum.jpg") bottom center;
  background-size: cover;
  background-repeat: no-repeat;
}
.keys {
  display: flex;
  flex: 1;
  min-height: 100vh;
  justify-content: center;
  align-items: center;
}
.key {
  border: 4px solid black;
  border-radius: 10px;
  margin: 10px;
  padding: 10px;
  font-size: 1rem;
  color: orangered;
  transition: all 0.07s;
  width: 90px;
  height: 90px;
  text-align: center;
}
kbd {
  color: white;
  font-size: 4rem;
  display: block;
}
.playing {
  transform: scale(1.1);
  border-color: yellow;
  box-shadow: 0 0 10px #ffc600;
}