Cascading Stylesheets (CSS) have been with us since 1996, making them one of the oldest staples of the Web, even though they only reached widespread popularity with the tables versus CSS wars of the early 2000s.
You're probably familiar with using CSS for styling HTML. So, this section will be a refreshing breeze after all that weird-looking SVG stuff.
My favorite thing about CSS is its simplicity; consider the following code:
selector {
attribute: value;
}
That describes CSS better than I can--you use selectors to modify properties using values. Although there's a bit more to it, particularly in terms of how properties cascade down the DOM tree, the above is pretty much it.
We've been using selectors all this time. A selector is any string that describes one or more elements in a DOM tree.