CSS structure

One component per file

For each component, place them in their own file.

/* css/components/search-form.scss */
.search-form {
  > .button { /* ... */ }
  > .field { /* ... */ }
  > .label { /* ... */ }

  // variants
  &.-small { /* ... */ }
  &.-wide { /* ... */ }
}

Use glob matching

In sass-rails and stylus, this makes including all of them easy:

@import 'components/*';

Avoid over-nesting

Use no more than 1 level of nesting. It's easy to get lost with too much nesting.

/* ✗ Avoid: 3 levels of nesting */
.image-frame {
  > .description {
    /* ... */

    > .icon {
      /* ... */
    }
  }
}

/* ✓ Better: 2 levels */
.image-frame {
  > .description { /* ... */ }
  > .description > .icon { /* ... */ }
}