body {
  text-align: center;
  background-color: #011F3F;
  font-family: 'Karla',sans-serif;
}

#level-title {
  font-size: 2.5rem;
  margin:  5%;
  color: white;
}
.instr{
  text-align: left;
  font-size: 1.5rem;
  margin:3%;
  color: white;
}
.para{
  margin-top: -3%;
}
.foot{
  text-align: conter;
  font-weight: lighter;
  font-size: 0.9rem;
  margin:5%;
  color: white;
}
.container {
  display: block;
  width: 50%;
  margin: auto;

}

.btn {
  margin: 25px;
  display: inline-block;
  height: 200px;
  width: 200px;
  border: 10px solid black;
  border-radius: 20%;
}

.game-over {
  background-color: red;
  opacity: 0.8;
}

.red {
  background-color: #ffad99;
}

.green {
  background-color: #99ff99;
}

.blue {
  background-color: #b3d9ff;
}

.yellow {
  background-color: #ffffb3;
}

.pressed {
  box-shadow: 0 0 20px white;
  background-color: grey;
}