Implementing Simple Dark Mode with CSS light-dark()

Fri, 10 Oct 2025 00:00:00 +0900

The Problem with Traditional Dark Mode

Implementing dark mode traditionally required duplicate CSS rules wrapped in @media (prefers-color-scheme: dark):

:root {
 --bg: #ffffff;
 --text: #111111;
}

@media (prefers-color-scheme: dark) {
 :root {
 --bg: #1a1a2e;
 --text: #e0e0e0;
 }
}

This works but creates maintenance overhead, especially when managing multiple color properties across large stylesheets. The light-dark() CSS function eliminates this duplication entirely.

The light-dark() Function

The light-dark() function accepts two color values and automatically returns the one matching the user’s current color scheme:

Dark-Mode on Commentary of Takao

Implementing Simple Dark Mode with CSS light-dark()

The Problem with Traditional Dark Mode

The light-dark() Function