14 lines (14 loc) · 1.38 KB

Design web pages with CSS

what is css ?

CSS stands for Cascading Style Sheets ,it is describes how HTML elements are to be displayed on screen, paper, or in other media .

css work as imagin that there is invisable box around every Html element and allow to create rules that control the way that each individual box is presenrtd

a css rules contain selector and declaration , declarations site inside curly brackets and each is made up of two parts: property and value separated by a colon.

css selectors :

You can specify any color in CSS in one of three ways:

rgb values These express colors in terms of how much red, green and blue are used to make it up, are expressed as numbers between 0 and 255
hex Codes These are six-digit codes that represent the amount of red, green and blue in a color, preceded by a pound or hash # sign.
Color names There are 147 predefined color names that are recognized by browsers. For example: DarkCyan .

CSS3 introduces an entirely new and intuitive way to specify colors using hue, saturation, and lightness values.

CSS3 has introduced an extra value for RGB colors to indicate opacity. It is known as RGBA