CSS stands for Cascading Style Sheets, that is cascading style sheets. They include stylistic description of HTML tags, as it kind of Supplement. In essence, the style — a set of parameters for the object’s appearance. The difference of options object representation depends on the style. CSS is used by the creators of web pages to select different fonts and colors. Used by web pages with HTML and XHTML.
This set of descriptions can be used simultaneously for all identical tags, or to separate a specific element on the page.
the Advantages of CSS are:
1. Using parameters that are not supported in HTML.
2. A significant reduction in code size.
3. Easy to change the appearance of web pages. Even a few dozen pages can be changed simultaneously in the stylesheet.
To get started you should attach the stylesheet to the document. Here are some commonly used methods:
1. Embedding in the document elements. Here the desired style set specific HTML code.
2. The binding. The method is used when you want to set a specific style for all pages. This option is most suitable in case of creation of a website.
CSS choose to work with documents based on some important principles. These include cascading and inheritance. The first principle comes into use in the event of conflicting CSS rules. This happens when the HTML tag set a few rules. Because of this, and there is a conflict of inconsistencies. To resolve this conflict are precedence rules. The principle of inheritance means the transition CSS properties from one tag to another. The elements of the ancestors as would pass them by inheritance to his descendants.
There are several types of levels CSS:
— CSS1. Finally was corrected in 1999.
— CSS2. Based on the first level with the addition of additional functions. At the present time is not supported.
— CSS3. This level was based on CSS2.1.
— CSS4. The basis is taken from the third module. Developed in 2011. Today, the modules are in the form of drafts.
This set of styles to best support these browsers: Google Chrome, Mozilla Firefox and Opera. Internet Explorer 8 is more advanced than their predecessors. It fully supports CSS 2.1, and also partly CSS 3.