Directive @at-root in SASS

The @at-root directive is designed to extract rules from the parent selector to the root of the file.

Let's look at the following example with first-level nesting selectors:

style.scss.parent {
  background-color: #fdd;
  @at-root .child {
    border: 1px solid;
  }
}

As a result of compilation we got the following code:

styles.css.parent {
  background-color: #fdd;
}
.child {
  border: 1px solid;
}

Now let's look at how the @at-root directive works with multiple selectors:

style.scss.main-parent {
  background-color: #fdd;
  @at-root {
    .first-child {
      border: 1px solid;
    }
    .second-child {
      font-weight: bold;
    }
  }
  .step-child {
    color: #232523;
  }
}

After compilation, the code looks like this:

styles.css.main-parent {
  background-color: #fdd; 
}

.first-child {
  border: 1px solid; 
}

.second-child {
  font-weight: bold; 
}

.main-parent .step-child {
  color: #232523; 
}

styles.scss.primary-button {
  background-color: #3272c7;
  @at-root {
    .block-button {
      color: #ff0000;
    }
    .content-button {
      color: #ccb42a;
    }
  }
  .warning-button {
    border: 2px solid #232523;
  }
}