Generated by SassMeister.com.

SassMeister-input.scss

// ----
// libsass (v3.2.4)
// ----

//定義方法 animation-delay-n
@mixin animation-delay-seconds($n){
  &:nth-child(#{$n}){
    animation-delay: #{$n*2}s;
  }
}

div {
  @include animation-delay-seconds(1);
  @include animation-delay-seconds(3);
  @include animation-delay-seconds(5);
}

SassMeister-output.css

div:nth-child(1) {
  animation-delay: 2s;
}

div:nth-child(3) {
  animation-delay: 6s;
}

div:nth-child(5) {
  animation-delay: 10s;
}