What are the new features that are introduced in CSS3?

One of CSS3's features is advanced animations.

When it is necessary to modify a component starting in one state and moving/transitioning onto the next, we can use both transition and animation. What matters is that animation can consist of a variety of states, allowing the user control over the animation. These animations are now accessible and work with every browser. There are two methods for creating CSS animations. The first method is straightforward; it involves animating CSS property progressions using the transition assertion.

Flexbox

It is significantly simpler for web developers to organise HTML components vertically or horizontally thanks to the CSS3 flexbox feature. Flexbox-based website layouts may adapt to users' different screen sizes, including those on mobile devices. The display property in CSS must be set to flex in order to utilise the feature, as shown below:

display: flex; main;