via smashingmagazine.com => original post link
CSS is mainly known as a language based on a set of property-value pairs. You select an element, define the properties, and write styles for it. There’s nothing wrong with this approach, but CSS has evolved a lot recently, and we now have more robust features, like variables, math formulas, conditional logic, and a bunch of new pseudo selectors, just to name a few.
What if I tell you we can also use CSS to create an array? More precisely, we can create an array of colors. Don’t try to search MDN or the specification because this is not a new CSS feature but a combination of what we already have. It’s like we’re remixing CSS features into something that feels new and different.
For example, how cool would it be to define a variable with a comma-separated array of color values: