CSS (Cascading Style Sheet, cascading style sheet) is used to beautify HTML web pages.
/*Comment area*/ This is the comment syntax
1. Style sheet
(1) Classification of style sheets
1.Inline style sheet
and HTML are jointly displayed, with precise control, but poor reusability and more redundancy.
Example:
Inline style sheet
2.Embedded style sheet
is embedded in the web page as an independent area and must be written in the head tag.
3.
External style sheet
Create a new CSS file to place the style sheet. If you want to call the style sheet in the HTML
file, you need to right-click →CSSStyle Sheet→ in the HTML file to attach the style sheet. Generally use link to connect. Some tags have default margins, which are generally removed when writing style sheet code (other styles can also be set), as follows:
1.Tag selector. Use tag name as selector.
2.class
Selector. They all start with 
3.ID
Selector. Start with 
Composite Selector
(1) is separated by " , ", indicating juxtaposition. (2) are separated by spaces to indicate descendants. (3) Filter ".". 2. Style attributes (1) Background and foreground 1.Background: 2.Foreground font: (2) Borders and borders border (table border, style, etc.), margin (outside table spacing). padding (content and cell spacing). (3) Lists and Blocks width, height, (top, bottom, left, right) are only useful in absolute coordinates. Linked style: a:link The state before the hyperlink is clicked a:visited Status after clicking the hyperlink a:hover When hovering over a hyperlink a:active When a hyperlink is clicked When defining these states, there is an order l v h a
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