Don't miss out on css variables

CSS variables (custom properties) are a native browser feature that can replace preprocessors like SCSS or SASS for many use cases. Declared with double-dash syntax and accessed via the var() function, they support fallback values and cascade through the DOM. A key advantage is theming: by toggling a class on the body element, all dependent variables update automatically for light/dark themes. The JavaScript API (getPropertyValue and setProperty) enables dynamic runtime manipulation of CSS variables, opening up interactive use cases like a drag-to-select box that updates four corner coordinates via mouse events.