.slider {
  max-width: 400px;
  margin: 0 auto;
}

.slider__input {
  width: 100%;
}

.slider__image {
  display: block;
  margin: 20px auto;
  max-width: 100%;
  transition: all 0.1s;
}

#box {
  width: 50px;
  height: 50px;
  background-color: red;
  position: absolute;
}

#buttonStart{
  padding: 10px;
  background-color: aqua;
  transition: transform 0.1s;
  color: black;
  font-family: Verdana, Geneva, Tahoma, sans-serif;
  margin-left: 100px;
}