SCSS rule Inheritance compared to LESS - less

Question

I'm used to using LESS but im currently working with SCSS.
In Less I could do the following:
.sidebar_styles { background: red; border: 1px solid blue; }
aside[role="complementary"] { .sidebar_styles; }
Would the SCSS equivalent be:
.sidebar_styles { background: red; border: 1px solid blue; }
aside[role="complementary"] { #extend .sidebar_styles; }
I ask as I am using the Foundation framework and I'm trying to not use presentation classes in the html. I noticed Chrome was running slowly and opened up the inspector. The matched css rules for some elements is huge.
Below is about 5% of what I could copy from one of the elements before Chrome hangs.
.row.collapse .column, body.full_width div[role="main"] form .row.collapse .column, body.two_columns div[role="main"] form .row.collapse .column, body.homepage div[role="main"] .hero_container form .row.collapse .column, .row form .collapse.top_bar .column, .top_bar form .collapse.top_bar .column, header[role="banner"] form .collapse.top_bar .column, footer[role="contentinfo"] form .collapse.top_bar .column, body.full_width div[role="main"] form .collapse.top_bar .column, body.two_columns div[role="main"]

Answer 1

#extend will group the css selectors together in comma separated list. If you add additional rules after the #extend, it will keep those rules as it's own selector.
scss
.sidebar_styles {
background: red;
border: 1px solid blue;
}
aside[role="complementary"] {
#extend .sidebar_styles;
color: black;
}
css output
.sidebar_styles, aside[role="complementary"] {
background: red;
border: 1px solid blue;
}
aside[role="complementary"] {
color: black;
}
If you want to keep the rules separated then you can use a mixin and include it in the rules.
scss
#mixin test {
background: red;
border: 1px solid blue;
}
.sidebar_styles {
#include test;
}
aside[role="complementary"] {
#include test;
}
css output
.sidebar_styles {
background: red;
border: 1px solid blue;
}
aside[role="complementary"] {
background: red;
border: 1px solid blue;
}