- Better degree of formatting

- Easily maintainable websites

- Faster to access

- Quicker to download

- Can be adopted for different mediums

CSS Versions

W3C published the CSS Level 1 Recommendation in 1996.
A year later, the CSS Level 2 Recommendation
CSS2.1, become an official W3C Recommendation until June 2011.
CSS2.1 standard was being worked on, a different group at the W3C was working on a CSS3 draft.

Browser Adoption

While Microsoft’s Internet Explorer was an early champion of CSS, its later versions (especially IE5, IE6, and IE7) for Windows had uneven support for certain parts of CSS2.
In fact, all browsers have left certain parts of the CSS2 Recommendation unimplemented.
CSS has a reputation for being a somewhat frustrating language.

CSS Syntax

Properties

Element Selectors

selects all instances of a given HTML element

Grouped Selector

Universal Selector

Inheritance selector

Class Selectors

Simultaneously target different HTML elements

Target a specific element by its ID attribute

Selecting via presence of element attribute or by the value of an attribute

Select something that does not exist explicitly as an element

Select elements based on their ancestors, descendants, or siblings

Cascade: Styles Interact

Principles to handle cascades (conflicts)

Specificity Algorithm

Location

When inheritance and specificity cannot decide

Box Model

think inside the box

Collapsing Margins

The width and height properties specify the size of the element’s content area.
Only block-level elements and non-text inline have a width and height.
By default the width of and height of elements is the actual size of the content.
For text, it is font size and font face;
For images - the width and height of the actual image in pixels