What does the "=" sign mean in sass?

Question

css

In the project, you need to use styles from the following structures:

=body1
    font-family: OpenSans
    font-size: 28px
    font-weight: 600

    @media (max-width: $mobile)
        font-size: 24

What is it and how can I use it to set the font for an element?

Answer 1

sass-lang.com/documentation/file.SASS_REFERENCE.html
as I understand it, this is a mixin.
use like this:

+body1
    .elem

but this is some very old syntax. use SCSS . 2018 is in the yard.