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: lavender;
    --tag-text-color: #{darken(lavender, 20%)};

    // Admonition
    --note-color: #{$linkColor};
    --note-background-color: var(--link-hover-color);
    --warning-color: rgb(208, 126, 25);
    --warning-bg-color: rgb(255, 250, 202);

    // Syntax Highlighting
    --astro-code-color-text: #24292e;
    --astro-code-color-background: inherit;
    --astro-code-token-constant: #005cc5;
    --astro-code-token-string: #1f9554;
    --astro-code-token-comment: #6a737d;
    --astro-code-token-keyword: #d73a49;
    --astro-code-token-parameter: #24292e;
    --astro-code-token-function: var(--astro-code-color-text);
    --astro-code-token-string-expression: #032f62;
    --astro-code-token-punctuation: #000007;
    --astro-code-token-link: #3b77a9;
  }
}

@media (prefers-color-scheme: dark) {
  $backgroundColor: hsl(230, 20%, 16%);
  $textColor: #cdcdcd;
  $linkColor: hsl(211, 83%, 75%);
  $linkHoverColor: #202749;

  :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: #{$linkColor};
    --link-hover-color: #{$linkHoverColor};
    --code-color: #{lighten(firebrick, 25%)};
    --tag-color: #{darken($linkColor, 55%)};

    // Admonition
    --note-color: #{$linkColor};
    --note-background-color: var(--link-hover-color);
    --warning-color: rgb(211, 185, 107);
    --warning-bg-color: rgb(40, 43, 14);

    // Syntax Highlighting
    --astro-code-color-text: #e1e4e8;
    --astro-code-color-background: inherit;
    --astro-code-token-constant: #79b8ff;
    --astro-code-token-string: #9ecbff;
    --astro-code-token-comment: #6a737d;
    --astro-code-token-keyword: #f97583;
    --astro-code-token-parameter: #e1e4e8;
    --astro-code-token-function: var(--astro-code-color-text);
    --astro-code-token-string-expression: #85e89d;
    --astro-code-token-punctuation: #ffab70;
    --astro-code-token-link: black;
  }
}