* {
  margin: 0;
  padding: 0;
}

section {
  width: 800px;
  margin: 10px auto;
  padding: 20px;
  background-color: white;
  border-radius: 10px;
}

@media screen and (max-width: 800px) {
  section {
    width: 100%;
    margin: 0;
    padding: 10px;
    border-radius: 0;
  }
}