chore: migrate away from deprecated scss lighten/darken

Author: valeriansaliou

package-lock.json

@@ -8,22 +8,10 @@
  * TOOLS > FUNCTIONS
  * **************************************************************************/
 
-@function hex-var($color) {
-  @return red($color) + ", " + green($color) + ", " + blue($color);
+@function lighten-color($color, $percent) {
+  @return color.adjust($color, $lightness: $percent);
 }
 
-@function color-mix-var($base, $color, $percent) {
-  @return color-mix(in srgb, rgb($color) (100% - $percent), rgb($base));
-}
-
-@function lighten-var($color, $percent) {
-  // Notice: apply a corrective factor to the percent so that it looks almost \
-  //   like SCSS lighten() function.
-  @return color-mix-var(var(--color-white), $color, ($percent * 1.3));
-}
-
-@function darken-var($color, $percent) {
-  // Notice: apply a corrective factor to the percent so that it looks almost \
-  //   like SCSS darken() function.
-  @return color-mix-var(var(--color-black), $color, ($percent * 1.3));
+@function darken-color($color, $percent) {
+  @return color.adjust($color, $lightness: -$percent);
 }