h3,
h1,
h2 {
  text-align: center;
}

main {
  max-width: 90%;
}

#earth {
  width: 70%;
  margin: auto;
  display: block;
}

@media screen and (max-width: 650px) {
  #earth {
    width: 100%;
    margin: auto;
    display: block;
  }
}