* {
  box-sizing: border-box;
}
body {
  margin: 0;
  padding: 0;
  font-family: sans-serif;
  position: relative;
  font-size: 10px;
}

body:before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url(../images/animal.jpg) bottom center;
  background-size: cover;
  z-index: -1;
}

.keys {
  display: flex;
  flex: 1;
  flex-wrap: wrap;
  min-height: 100vh;
  align-content: center;
  justify-content: center;
}

.key {
  border: 0.4rem solid whitesmoke;
  border-radius: 0.5rem;
  margin: 1rem;
  font-size: 1.5rem;
  padding: 1rem 0.5rem;
  transition: all 0.07s ease;
  width: 10rem;
  text-align: center;
  color: white;
  background: rgba(0, 0, 0, 0.8);
  text-shadow: 0 0 0.5rem black;
}

.key.is-playing {
  transform: scale(1.1);
  border-color: #ffc600;
  box-shadow: 0 0 1rem #ffc600;
}

.key kbd {
  display: block;
  font-size: 4rem;
}

.key span {
  font-size: 1.2rem;
  text-transform: uppercase;
  letter-spacing: 0.1rem;
  color: #ffc600;
}

.playing {
  transform: scale(1.1);
  border-color: #ffc600;
  box-shadow: 0 0 1rem #ffc600;
}


.info {
  background-color: rgba(0, 0, 0, 0.8);
  margin: 0 auto;
  padding: 0.625rem;
  color: white;
  max-width: 37.5rem;
  border: 0.4rem solid whitesmoke;
  border-radius: 0.5rem;
  font-size: 1.25rem;
  line-height: 1.5rem;
  text-align: center;
}

.margin {
  margin: 1rem 0.5rem;
}