...but are always worth mentioning, because they're incredibly cool compared to vanilla CSS:
Familiar way:
a {
&:hover {
color: red;
}
}
Compiles into:
/* compiled CSS */
a:hover {
color: red;
}
But can be used with a prefix just as well:
p {
body.no-touch & {
display: none;
}
}
Gives you:
/* compiled CSS */
body.no-touch p {
display: none;
}
...or almost anywhere else, for that matter.
...with multiple inheritance.
...and expanding and/or extending during further calls.