What does the number 3 in CSS3 technology mean?

When discussing CSS3, the number "3" indicates that this is Cascading Style Sheetsthe third version of CSS (, Cascading Style Sheets). CSS is a stylesheet language used to describe how HTML (or XML and SVG) documents are rendered or displayed. CSS3 is not a single specification, but a series of modules, each with its own independent functions and features.

The following are some main features and application examples of CSS3 technology:

1. Selectors: CSS3 introduces many new selectors that allow developers to select and modify elements more easily and precisely. For example, CSS3 allows the use of attribute selectors, which can select elements based on their attributes and attribute values. For example, input[type="text"]selects all input elements of type text.

There are a lot of selector use cases in the Spartacus scss file below:

2. Borders and Backgrounds: CSS3 adds control over borders and backgrounds. For example, you can border-radiuscreate rounded borders with , box-shadowadd shadows to elements with , or background-sizecontrol the size of background images with .

The following are specific examples:

3. Animations and transitions: CSS3 introduces animations and transitions, allowing page elements to achieve smooth dynamic effects without using JavaScript. For example, properties can be used transitionto change certain styles of elements over time, or @keyframesrules and animationproperties can be used to create complex animations.

4. Layout: CSS3 provides many new layout tools, such as Flexbox and Grid, which make it easier to create complex responsive layouts. For example, you can display: flexcreate a flex layout with , or display: gridcreate a grid layout with .

5. Media Queries: CSS3 introduces media queries, which allow styles to be adjusted based on device characteristics such as viewport width or device orientation. For example, you can use @mediarules to create a style that modifies the layout or style of an element when the viewport width is less than 600px.

6. 2D/3D transformation: CSS3 introduces 2D and 3D transformation functions, enabling elements to achieve various transformation effects without using JavaScript. For example, you can use transformproperties to rotate, scale, skew or move elements.

7. Text and fonts: CSS3 has also enhanced the control of text and fonts. For example, rules can be used @font-faceto import custom fonts, or to text-shadowadd text shadows.