.content {
  margin: 0 auto 20px auto;
  background-color: rgb(194, 206, 223);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items:center;
  font-size: 22px;
}
#s1 {
  width: 200px;
  height: 200px;
}
#s2 {
  width: 400px;
  height: 600px;
}
#s3 {
  width: 700px;
  height: 300px;
}
#s4 {
  width: 500px;
  height: 500px;
}