$border-radius-data: (
  small: 2px,
  base: 4px,
  large: 8px,
);

/// Returns the border radius of the specified size.
/// @param {String} $size - The border radius’s size.
/// @return {Number} The border radius value.

@function border-radius($size: base) {
  @return map-get($border-radius-data, $size);
}