Explain 20 lines of CSS I m a novice

I don't know much about that.

CSS, DW with annotation tools, you find the following tools, there are several ways to annotate.

*--Comment content --

There are tools with annotations in DW, and you find the tools below, which have several ways to annotate.

For example: *--navigation start--*

--End of Navigation --*

CSS rules are annotated with *content that needs to be annotated*, i.e. annotating begins with a "*" tag before the content that needs to be annotated, and ends with a "*" at the end of the content. Annotations can be annotated on multiple lines of content. Its annotation ranges between "*" and "*".

Here's an example to illustrate the use of annotations:

header

If you don't reach the Yellow River, you won't die.

If you don't get to the point where you have no way out, you won't give up. The parable does not stop until it reaches its goal.

Very attached to something, praise.

The synonym is: if you don't go to the Great Wall, you are not a hero.

Derogatory: If you don't go into the coffin, you don't shed tears.

It is added to prevent some older browsers from not supporting CSS styles, and if you don't add CSS**, it will be displayed on the browser. */

td a:hover

a imgimg1

bluebgcolor

btn_grey

txt_grey

word_grey

word_deepgrey

word_orange

word_blue

word_white

word_gray

bodytextarea

shadow

shadow_1

shadow_2

shadow_3

tableborder

hidden_a_line

You can check the API documentation for more detail.

Brother, it's the era of HTML5+CSS3 now, and you still play IE's filter as a shadow? You don't post a web page**How do I know? Besides, this stylesheet is largely ineffective in modern browsers.

Too much, write to when oh @!

CSS can be annotated with **.

If you can use it in the annotation to add the entire style.

Here is the comment for CSS.

#id1

Can be split into:

background-color:#016aa9 ;*Background color, displayed in the background**out of place*

Background: Address

background-reapeat:no-reapeat ;*Background film is not re-paved*

background-attachment : scroll ;* Scroll with content. Relative to fixed, it doesn't scroll with content*

background-position: center top *** positioning. Left and right centered, up*

This is an abbreviation for all background-related CSS properties.

016aa9 This is the background color, which is equivalent to the background-color;

url(images is the background**, equivalent to.

no-repeat is set to the background is not tiled, which is equivalent to background-reapeat:no-reapeat;

The scroll is set to the background to scroll with the content, which is equivalent to background-attachment : scroll (in layman's terms: whether to let the background be fixed in a certain place in the browser window, scroll is not fixed, and there is also a property fixed to be fixed, which is more abstract to say, it is recommended that you operate it once, it is easy to understand).

center top is the position of the background** relative to the window, which is set in the order of the X and Y axes, which is equivalent to background-position: center top (center means in the middle of the X axis of the container, and top is the top of the container (for example: for example, if a window is 200px wide and 600px high, then the background** runs to the position of 100px on the x-axis and 0 on the y-axis), and it is also recommended that you actually operate it once, Operation is always more practical than fantasy).

The background color is set to 016aa9; Background**display images, background** is not displayed repeatedly, horizontally centered, pinned;

The background ** is not repeated, so the layer is too large, and the place that the background ** does not cover is the background color 016aa9.

This is to set the line-height property in CSS.

It's the line height, and it doesn't have to be set. Most of the time you can do without this attribute.

Blank means the default value, the default is px.

line-height = font-size + word-spasing

For example, if the line height is set to 100px, if the character size is 40px, the uplink and downlink spacing will be 30px.

The point is: the size of the upper and lower line spacing of characters is the same.

Line-height is a common application when setting text centering.

The drop-down is all units, and when the attribute value is a numeric value, it must be with a unit to take effect, such as: ; If there are no units, then this one is meaningless. But there is one case where units are not needed, and that is when using keywords, such as:

line-height:normal;Indicates that the default value is used.

line-height: It means line height.

For example, line-height:30px; It will be centered in a height of 30px and adjust the effect of line spacing of the text.

The line height is the height of a line of text.

Blank is the default, or inherits the properties of the parent element.

White space is not the default unit, line-height: means: line height is a multiple of the font size.

is to set the distance between rows.

Here's how it works:

123 you can control. b's top, right, bottom, left, four properties to control the position.

position:abslute;Absolute positioning.

When absolute positioning is set, top:0; Sets the distance from the top edge.

right:0;Sets the distance to the right.

???Define who's? These are the 3 properties of CSS. Absolute positioning, in the upper right part of the page.

The architecture of the browser is window, document, html> is the visible part, document is the physical part of the web page (including the off-screen part), and the body is the visible part (in principle).

The explanation is:

body: The margins and spacing of the page are 0, the background is a background image, and all text is centered by default.

potop,.pobottom: Both containers are 20 pixels wide and high, with a background image, positioned relative (20 pixels on the left), where the potop is 40 pixels above and the pobottom is 20 pixels below.

p: class is the container of p, relative positioning, width and height are 20 pixels, there is a background image (** is missing a parentheses); Hide.

Isn't it possible to define only one at a time?

A: No, it can be defined as such.

Multiple can be defined, and the hover can look something like this:

#body li a:hover,#mydiv a:hover