Return min size.

• If $size is key of $_size, return that value.
• If $size is number, return this.

scss

//
// @param  size|length  $size
// @return length|false
//

@use "node_modules/sass-basis/src/css/core";

@media (min-width: core.min(md)) {
  ...
}

Return max size.

• If $size is key of $_size, return that max value.
• If $size is number, return this.

scss

//
// @param  size|length  $size
// @return length|false
//

@use "node_modules/sass-basis/src/css/core";

@media (max-width: core.max(md)) {
  ...
}

Return prev key of $_size

scss

//
// @param  size  $size
// @return size
//

@use "node_modules/sass-basis/src/css/core";

$prev_size_key: core.prev-size-key(md); // => sm

Return next key of $_size

scss

//
// @param  size  $size
// @return size
//

@use "node_modules/sass-basis/src/css/core";

$next_size_key: core.next-size-key(md); // => lg