Sass @content

gistfile1.scss

// Example

@mixin hoge {
  p {
    color: red;
    @content;
  }
}

.alert {
  @include hoge;
}

.danger {
  @include hoge{
    font-weight: bold;
  }
}

// Reslt
.danger p {
  color: red;
  font-weight: bold;
}