body {
  min-width: 300px;
}

header,
main {
  margin: 0;
  padding: 0;
}

section {
  margin-bottom: $gutter;
  padding: $gutter;

  &:nth-of-type(even) {
    background-color: $light-grey;
  }
}

footer {
  margin: 0;
  padding: 0 $gutter;
}

@media screen and (min-width: 900px) {

  section {
    padding: ($gutter * 2) calc((100% - 850px) / 2);
    width: 850px;
  }

  footer {
    padding: 0 calc((100% - 850px) / 2);
    width: 850px;
  }

}