html {
  height: 100%;
}

body {
  height: 100%;
  margin: 0;
  padding: 0;
  background-color: #a3125b;
}

#cabecera {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 10%;
}

span {
  font-size: 30px;
  font-family: Arial;
  color: white;
}

#contenedor {
  height: 90%;
  display: flex;
  align-items: center;
  justify-content: center;
}

#piano {
  display: flex;
  position: relative;
}

.tecla-blanca {
  background-color: white;
  height: 120px;
  width: 40px;
  border: 1.5px solid black;
  border-radius: 0 0 6px 6px;
}

.tecla-negra {
  background-color: black;
  height: 80px;
  width: 20px;
  border: 1.5px solid black;
  position: absolute;
  border-radius: 0 0 5px 5px;
}

.REb4 {
  left: 30px;
}

.MIb4 {
  left: 70px;
}

.SOLb4 {
  left: 150px;
}

.LAb4 {
  left: 190px;
}

.SIb4 {
  left: 230px;
}

.REb5 {
  left: 310px;
}

.MIb5 {
  left: 350px;
}

/* .tecla-blanca: */
.active {
  background-color: #aaa;
}