body { min-width: 300px; } header, main { margin: 0; padding: 0; } section { margin-bottom: $gutter; padding: $gutter; &:last-of-type { margin-bottom: 0; } } @media screen and (min-width: 900px) { section { padding: ($gutter * 2) calc((100% - 850px) / 2); width: 850px; } }