1. CSS syntax and selectors

A CSS rule consists of two main parts: a selector, and one or more declarations:

H1 {color:blue; font-size:12px;}

Selectors are usually HTML elements that you need to change the style.
Each declaration consists of an attribute and a value.
property is the style property that you want to set. Each property has a value. Attributes and values are separated by colons.

CSS Comments:

/* It's a note . */

Priority of the selector:

Label internal STYLE > ID > class > tag Selector

Tag Selector instance:

< style > H3 {color:red; }</style><h3> Beginner's Tutorial  </h3>

ID selector:

The ID selector can specify a pending style for an HTML element that is labeled with a specific ID.

The HTML element sets the ID selector with the id attribute, and the ID selector in the CSS is defined by adding "#":

HTML--->

id = prar1

CSS--->

#para1 {text-align:Center; color:red;}

Class selector:

The lass selector is used to describe the style of a set of elements, which differs from the ID selector, and class can be used in multiple elements.

The class selector is represented in the HTML as a class attribute, and in CSS, the category selector takes a point "." Number display:

. Center {text-align:centr;}

You can also specify specific HTML elements to use the ClassA selector:

H1.center {text-align:Center}

1. CSS syntax and selectors