Updating a CSS Variable with JavaScript

Here’s a CSS variable (formally called a “CSS custom property”): :root { –mouse-x: 0px; –mouse-y: 0px; } Perhaps you use them to set a position: .mover { left: var(–mouse-x); top: var(–mouse-y); } To update those values from JavaScript, you’d: let root = document.documentElement; root.addEventListener(“mousemove”, e => { root.style.setProperty(‘–mouse-x’, e.clientX + “px”); root.style.setProperty(‘–mouse-y’, e.clientY + “px”); … Continue reading Updating a CSS Variable with JavaScript