Update jekyll

css/main.scss

@@ -4,6 +4,7 @@
 
 @charset "utf-8";
 
+@use 'sass:color';
 
 // Our variables
 $base-font-family: 'Share Tech', sans-serif;
@@ -18,8 +19,8 @@ $background-color: #d2d4bc;
 $brand-color: #2a7ae2;
 
 $grey-color: #828282;
-$grey-color-light: lighten($grey-color, 40%);
-$grey-color-dark: darken($grey-color, 25%);
+$grey-color-light: color.adjust($grey-color, $lightness: 40%, $space: hsl);
+$grey-color-dark: color.adjust($grey-color, $lightness: -25%, $space: hsl);
 
 $on-palm: 600px;
 $on-laptop: 800px;