Experimental book page layout.
[wolnelektury.git] / src / wolnelektury / static / 2021 / css / utils / bourbon / utilities / _lightness.scss
1 @charset "UTF-8";
2
3 /// Programatically determines the lightness of a color.
4 ///
5 /// @argument {color (hex)} $hex-color
6 ///
7 /// @return {number (0-1)}
8 ///
9 /// @example scss
10 ///   _lightness($color)
11 ///
12 /// @access private
13
14 @function _lightness($hex-color) {
15   $-local-red-raw: red(rgba($hex-color, 1));
16   $-local-green-raw: green(rgba($hex-color, 1));
17   $-local-blue-raw: blue(rgba($hex-color, 1));
18
19   $-local-red: _gamma($-local-red-raw / 255);
20   $-local-green: _gamma($-local-green-raw / 255);
21   $-local-blue: _gamma($-local-blue-raw / 255);
22
23   @return $-local-red * 0.2126 + $-local-green * 0.7152 + $-local-blue * 0.0722;
24 }