html {
  font-size: 10px;
  background: url('./image.jpg') bottom center;
  background-size: cover;
}
body,html {
  margin: 0;
  padding: 0;
  font-family: 'Courier New', Courier, monospace;
}
.instruction{
  width: 550px;
  height: 150px;
  background-color: #FFF;
  border: #ff000d 1px solid;
  margin: 0 auto;
  padding: 10px;
}
h1{
  text-decoration: underline;
}
h1,p{
  text-align: center;
  font-size: 15px;
  font-weight: bold;
}
.red{
  color: #ff000d;
}
.keys {
  display: flex;
  flex: 1;
  min-height: 100vh;
  align-items: center;
  justify-content: center;
}

.key {
  border: .4rem solid black;
  border-radius: .5rem;
  margin: 1rem;
  font-size: 1.5rem;
  padding: 1rem .5rem;
  transition: all .07s ease;/*vitesse a laquelqe la boite se modifie : taille/couleur*/
  width: 10rem;
  text-align: center;
  color: white;
  background: rgba(0,0,0,0.4);
  text-shadow: 0 0 .5rem black;
}

.playing {
  transform: scale(1.1);/*change la taille des block de lettre*/
  border-color: #ff000d;
  box-shadow: 0 0 1rem #ff0000;
}

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

.sound{
  display: none
}

.key:hover > .sound{
  display: inline-block;
  font-size: 1.5rem;
  text-transform: uppercase;
  letter-spacing: .1rem;
  color: #ff0000;


}