Implementing CSS Dark Mode

published on in category CSS , Tags: CSS Mojave Apple

I just recognized that this is the first ever post on CSS I do here. This will change. With macOS 10.14.4 Apple released Safari 12.1 which supports the prefers-color-scheme media query. This can be used to provide a the user with either a dark or a light user interface depending on the operating system setting. So I decided to implement it for my blog.

Since I changed my blog to a darker color scheme based on Dracula a few months ago, I thought it might be a cool feature to bring back the old (red & white) color scheme to people with a light user interface. Dark Mode with Safari on macOS Mojave

There’s a new CSS @media property called prefers-color-scheme that can be set to either light, dark or no-preference. I decided to create CSS variables that can then just be exchanged by the prefers-color-scheme media query. They are now supported in almost all browsers (except for IE which I don’t care about). So I exchanged all places where I used colors in my CSS by something like this:

button {
    background-color: var(--input-bg-color);
    color: var(--input-text-color);
    border: 1px solid var(--input-border-color);

The variables are defined on the very top of my stylesheet within the :root pseudo selector which makes them global for the document:

:root {
    --main-bg-color: #ffffff;
    --main-text-color: #000000;
    --headline-text-color: #666;
    --input-border-color: #f1362f;
    --input-text-color: #000000;

@media (prefers-color-scheme: dark) {
    :root {
        --main-bg-color: #282a36;
        --main-text-color: #f8f8f2;
        --headline-text-color: #8be9fd;
        --input-border-color: #bd93f9;
        --input-text-color: #f8f8f2;

In the Safari Developer Tools there’s a new switch now in the “Elements” tab that allows you to toggle the prefered color scheme.

Safari 12.1 Developer Tools Switch to Dark Mode

Further Reading

I run this site without advertisement of any kind. All information is free and my only goal is to give back something to the amazing free software development community. If you find some value in this, please consider donating me a cup of coffee using PayPal. Thank you so much!