CSS @ Rules: A CSS rule is a grouping of one or more CSS properties which are to be applied to one or more target HTML elements.
Types of CSS @ Rules
There are 4 types of CSS @ rules,
- The @import: rule imports another style sheet into the current style sheet.
- The @charset: rule indicates the character set the style sheet uses.
- The @font-face: the rule is used to exhaustively describe a font face for use in a document.
- The ! important: rule indicates that a user-defined rule should take precedence over the author’s style sheets.
The @import rule
The @import rule allows you to import styles from another style sheet. It should appear right at the start of the style sheet before any of the rules, and its value is a URL.
The @import rule Example
It can be written in the following way
<style type = "text/css">
<!--
@import "mystyle.css";
or
@import url("mystyle.css");
.......other CSS rules .....
-->
</style>
The significance of the @import rule is that it allows you to develop your style sheets with a modular approach. You can create various style sheets and then include them wherever you need them.
The @charset Rule
If you are writing your document using a character set other than ASCII or ISO-8859-1 you might want to set the @charset rule at the top of your style sheet to indicate what character set the style sheet is written in.
The @charset rule must be written right at the beginning of the style sheet without even space before it. The value is held in quotes and should be one of the standard character-sets.
The @charset Rule Example
<style type = "text/css"> <!-- @charset "iso-8859-1" .......other CSS rules ..... --> </style>
The @font-face Rule
The @font-face rule is used to exhaustively describe a font face for use in a document. @font-face may also be used to define the location of a font for download, although this may run into implementation-specific limits.
In general, @font-face is extremely complicated, and its use is not recommended for any except those who are expert in font metrics.
The @font-face Rule Example
<style type = "text/css">
<!--
@font-face {
font-family: "Scarborough Light";
src: url("https://tutorials.freshersnow.com");
}
@font-face {
font-family: Santiago;
src: local ("Santiago"),
url("https://tutorials.freshersnow.com")
format("truetype");
unicode-range: U+??,U+100-220;
font-size: all;
font-family: sans-serif;
}
-->
</style>
The ! important Rule
Cascading Style Sheets cascade. It means that the styles are applied in the same order as they are read by the browser. The first style is applied and then the second and so on. The ! the important rule provides a way to make your CSS cascade. It also includes rules that are to be applied always. A rule having a ! the important property will always be applied, no matter where that rule appears in the CSS document.
The ! important Rule Example
In the following style sheet, the paragraph text will be black, even though the first style of property applied is red:
<style type = "text/css">
<!--
p { color: #ff0000; }
p { color: #000000; }
-->
</style>
So, if you wanted to make sure that a property always applied, you would add the! important property to the tag. So, to make the paragraph text always red, you should write it as follows
<html>
<head>
<style type = "text/css">
p { color: #ff0000 !important; }
p { color: #000000; }
</style>
</head>
<body>
<p>Tutorials.freshersnow.com</p>
</body>
</html>
Here you have made p { color: #ff0000 !important; } mandatory, now this rule will always apply even you have defined another rule p { color: #000000; }.