CSS

Updating CSS Variables with Javascript

If you are building an application or SaaS platform, or in fact any website, it can be useful to store all your colours as CSS variables, and then update these once to change the theme of the app.

Fortunately this is relatively straightforward to accomplish. Imagine you have your CSS variables set up like this:

    :root {
        --main-background: blue;
        --main-sidebar: red;
        /* Yes these colors do not match */
    }

:root CSS styles are stored on document.documentElement. So we can access all of its styles via that. So in JS, all we need to do is this:

    document.documentElement.style.setProperty("--main-background", "yellow");

More Tips and Tricks for CSS

• Stripe-Like Smooth Transition CSS Only Menu
• Automating CSS Dark Mode
• The Quick Guide to Dark Mode
• CSS Transitions
• CSS 3d Mosaic Parallax Effect
• A first look at CSS When and Else Statements
• CSS Animations
• A Complete Guide to How the CSS not Selector Works
• Set a div or block to its content's width in CSS
• CSS Units