CSS SYNTAX
A CSS rule set consists of a selector and a declaration block
A CSS comprises of style rules that are interpreted by the browser and then applied to the corresponding elements in your document. A style rule is made of three parts −
Selector − A selector is an HTML tag at which a style will be applied. This could be any tag like <h1> or <table> etc.
Property − A property is a type of attribute of HTML tag. Put simply, all the HTML attributes are converted into CSS properties. They could be color, border etc.
Value − Values are assigned to properties. For example, color property can have value either red or #F1F1F1 etc.
The Class Selectors
You can define style rules based on the class attribute of the elements. All the elements having that class will be formatted according to the defined rule
.block{
}
The ID Selectors
You can define style rules based on the id attribute of the elements. All the elements having that id will be formatted according to the defined rule.
#block{
}
This rule renders the content in black for every element with id attribute set to black in our document. You can make it a bit more particular. For example
h1 #block{
}
This rule renders the content in black for only <h1> elements with id attribute set to black.
The true power of id selectors is when they are used as the foundation for descendant selectors, For example
In this example all level 2 headings will be displayed in black color when those headings will lie with in tags having id attribute set to black.
You have seen the descendant selectors. There is one more type of selector, which is very similar to descendants but have different functionality. Consider the following example
This rule will render all the paragraphs in black if they are direct child of <body> element. Other paragraphs put inside other elements like <div> or <td> would not have any effect of this rule.
The Attribute Selectors
You can also apply styles to HTML elements with particular attributes. The style rule below will match all the input elements having a type attribute with a value of text
input[text=”text”]{
}
The advantage to this method is that the <input type = “submit” /> element is unaffected, and the color applied only to the desired text fields.
Grouping Selectors
You can apply a style to many selectors if you like. Just separate the selectors with a comma, as given in the following example
h1,h2,{
}
This define style rule will be applicable to h1, h2 and h3 element as well. The order of the list is irrelevant. All the elements in the selector will have the corresponding declarations applied to them.
You can combine the various id selectors together as shown below
#guy,#rot{
}
The CSS Universal Selector
The universal selector (*) selects all HTML elements on the page.
*{
}
