@import url(//fonts.googleapis.com/css?family=Lato:100,300,400,700,900,100italic,300italic,400italic,700italic,900italic)

=lato($fw: 400, $ls: 0, $fs: null, $tx-rendering: true)
  // $fw: フォントの太さ, $ls: 字間, $fs: フォントスタイル
  font-family: 'Lato', sans-serif
  font-weight: $fw
  @if not $ls == 0
    letter-spacing: $ls
  @if (not $fs == null)
    font-style: italic
  @if $tx-rendering
    text-rendering: optimizelegibility