blog/src/styles/_colors.scss

@media (prefers-color-scheme: light) {
  $backgroundColor: white;
  $textColor: #15202b;
  $linkColor: royalblue;

  :root {
    --background-color: #{$backgroundColor};
    --faded-background-color: #{darken($backgroundColor, 10%)};
    --shadow-color: #{darken($backgroundColor, 10%)};
    --heading-color: #{darken(royalblue, 10%)};
    --text-color: #{$textColor};
    --small-text-color: #6e707f;
    --smaller-text-color: #{lighten($textColor, 30%)};
    --faded: lightgray;
    --hr-color: lightgray;
    --link-color: #{$linkColor};
    --link-hover-color: #{lighten($linkColor, 35%)};
    --code-color: firebrick;
    --tag-color: #{lighten($linkColor, 35%)};
  }
}

@media (prefers-color-scheme: dark) {
  $backgroundColor: #202030;
  $textColor: #cdcdcd;
  $linkColor: lightskyblue;

  :root {
    --background-color: #{$backgroundColor};
    --faded-background-color: #{lighten($backgroundColor, 10%)};
    --shadow-color: #{lighten($backgroundColor, 10%)};
    --heading-color: #{lighten(lightskyblue, 20%)};
    --text-color: #{$textColor};
    --small-text-color: #{darken($textColor, 8%)};
    --smaller-text-color: #{darken($textColor, 12%)};
    --faded: #666;
    --hr-color: gray;
    --link-color: #{$linkColor};
    --link-hover-color: #{darken($linkColor, 60%)};
    --code-color: #{lighten(firebrick, 25%)};
    --tag-color: #{darken($linkColor, 55%)};
  }
}