* {
  margin: 0;
  padding: 0;
}
body {
  margin: 0 50px;
}
h2 {
  text-align: center;
  margin: 20px;
  margin-bottom: 150px;
}
.container {
  display: flex;
  justify-content: center;
}
.circle {
  width: 3vh;
  height: 3vh;
  border-radius: 100%;
  background-color: red;
  position: absolute;
  z-index: 5;
  top: 183px;
  left: 48%;
}
.action {
  margin-top: 32px;
  text-align: center;
}
.btn {
  display: inline-flex;
  text-decoration: none;
  color: white;
  padding: 5px 15px;
  margin: 5px;
  border-radius: 10px;
}
.stop {
  background-color: red;
}
.play {
  background-color: yellow;
}
.speed {
  background-color: green;
}
.speed-up {
  background-color: skyblue;
}

@media only screen and (min-width: 600px) {
  .circle {
    display: none;
  }
  h2 {
    font-size: xx-large;
  }
}