// Box
//
// A simple box style.
//
// A block is often styled as a box. However, this design component is
// not applied to any blocks by default; it is used as an example of how to
// build and document a CSS component.
//
// "box" is the name of our component, so we define a `.box` class that we can
// apply to any HTML element that needs the box styling. We also provide a
// `%box` placeholder selector so that we can easily extend the basic box
// component with `@extend %box;`.
//
// Take a look at the source code for this component for more information about
// building a good component.
//
// :hover - The hover/focus styling.
// .box--highlight - The "highlight" box variant.

.box,
%box {
  // Add vertical rhythm margins.
  @include margin-block(1);
  @include padding(.5);
  border: 5px solid var(--color-border);

  // Sass compiles this to the selector: .box__title, %box__title {}
  // The "__" (double underscore) is part of a BEM naming convention that
  // indicates the "title" is an _element_ of (a piece of) the "box" component.
  &__title,
  .title {
    margin-top: 0;
  }

  // Sass compiles this to the selector: .box--highlight, %box--highlight {}
  // The "--" (double dash) is part of a BEM naming convention that indicates
  // the "highlight" is a _modifier_, creating a new variation of the standard
  // "box" component.
  &--highlight {
    border-color: var(--color-highlight);
  }

  &--fit {
    width: fit-content;
  }

  &--gutter {
    padding-inline: var(--gutters);
  }

  &--inverted {
    @extend %link-inverted;
    background: var(--color-border);
    color: var(--color-text-bg);

    // Make sure headings etc. also gets inverted.
    * {
      color: var(--color-text-bg);
    }
  }

  > * {
    &:first-child {
      margin-top: 0;
    }

    &:last-child {
      margin-bottom: 0;
    }
  }
}