The first chapter on CSS Learning

1, CSS Three kinds of writing way: embedded, outside the chain, in-line

Embedded is the CSS write in <style></style>

outside the chain will be the outside CSS files are linked by tags in HTML : <link rel= "stylesheet" type= "Text/css" href= " external CSS The address of the file "/>

Inline: Is the CSS code written in < tag style="CSS code "/>

2. CSS selector: basic selector, composite selector, pseudo class selector, property selector

The basic selector is also divided into: Universal selector, Tag Selector, ID selector, class selector .

　　　　Universal Selector : *{declaration statement; it sets the style for all tags in HTML, which increases the burden on large Web sites and is not recommended.

Tag Selector : tag name { declaration statement ; Statement Statement ;}　　

　　　　class selector : The attribute value of the . Class { declaration statement ; Statement Statement ;} Common

ID Selector : The property value of the #id { declaration statement ;}

The composite selector is divided into: Combo selector: selector 1, selector 2, selector 3, selector n{ declaration statement; Declare statement} to set the style for the selector in the list at the same time

Descendant element selector: ancestor element descendant element { statement 1; Statement 2;} matches all descendant elements specified below the ancestor element to set the style

　　　　　　　　　　　child element Selector : parent element > child element { statement 1; Statement 2;} matches the specified child element below the parent element to set its style

　　　　　　　　　　　adjacent element selector : E + f{ Format declaration statement ;} Match E element below the F element, two elements must be next to each other

Pseudo-class selectors are used to set styles for different states of hyperlinks : a:link,a:visited{ Sets the color of hyperlinks ; Remove Underline ;} set pre-and post-access status

a:hover{ Set the color of the hyperlink ;} Set the state of the mouse on

3. List Style properties: List-style-type items before the modified list composite: none (None), disc (solid circle), Circle (Hollow Circle), Square (small square)

List-style-position setting the position of the pre-list symbol: Inside (inside), outside (on the outside, default value)

List-style-image set the pre-list symbol to Picture:list-style-image: url (picture path)

List-style Shorthand property: List-style:none url (picture path) inside

4. Inheritance and precedence: inline style >id selector > class selector > Tag Selector

5,!     Important: The weight value of the promoted attribute infinite format: attribute : attribute value !important; IE6 Browser does not support

6. Background style properties: Background-color set background color; Background-image Set background image, Background-repeat set background picture status: No-repeat (Uneven), repeat-x ( Tile horizontally),

Repeat-y (tile vertically), background-position: horizontal position or vertical position (set picture position) There are 3 ways of expression: English words, fixed values, percentages;

Background : Shorthand property, you can have multiple values ( to set the background color and background picture for an element if the element has height and width or content.)

The first chapter on CSS Learning