CSS3 has been in the works for over a decade. WebKit/Blink, Opera, and Firefox have been supporting some features for a long time now. With IE10 and IE11, we’re almost there! It’s time we took advantage of some awesome new (and sometimes not so new) features. Especially when it comes to CSS selector support, mobile browsers are there.
When you don’t have to worry about older versions of Internet Explorer (IE8 and earlier), you can use any CSS3 selector. All of them are supported in all modern browsers, and all of them are supported on all smartphone and tablet browsers.
The CSS2 specifications were adopted in 1998. CSS3 has been in development since then. The CSS3 specifications are still in development, and will likely never be finalized.
“Huh?” you ask. CSS 2.1 and earlier specifications were monolithic specifications. CSS3 is an umbrella term for all specifications after CSS 2.1. Instead of a monolithic specification, there are now modules for each CSS component, and new modules and new features keep getting added. Some of these specifications, like colors and selectors, are level 3, with work having commenced on level 4. Other specifications are at level 1. All of these modules, whatever the level, are under the umbrella called “CSS3.” Each module goes through the spec writing and finalization process at its own pace.
WebKit/Blink, Opera, and Mozilla have not waited for module specifications to be finalized. With Internet Explorer 9, Microsoft finally ...