What does css file margin mean?

css file margin is a css attribute used to define the space around the element; margin represents the outer margin. You can change the top, bottom, left, and right margins of the element individually, or you can change all attributes at once; the margin attribute Accepts any length unit, percentage value, or even negative values.

The operating environment of this tutorial: Windows 10 system, CSS3 version, DELL G3 computer

What does the css file margin mean?

CSS margin (margin) property defines the space around an element.

margin

margin clears the surrounding (outer border) area of ​​the element. The margin has no background color and is completely transparent.

margin You can change the top, bottom, left, and right margins of the element individually, or you can change all attributes at once.

#margin shorthand property sets the margin properties of all current or specified elements in a single declaration. This attribute can have 1 to 4 values.

The margin attribute accepts any length unit, percentage value or even negative value.

The margin attribute can change the top, bottom, left, and right margins of the element independently. It is also possible to change all properties at once.

Margin, like padding, also has a concise way of writing. We can use the margin attribute to set margins in four directions. In actual programming, we often use the efficient and concise writing method of margin to program.

There are 4 ways to write margin, as follows:

 margin: 像素值1;
 margin: 像素值1  像素值2;
 margin: 像素值1  像素值2  像素值3;
 margin: 像素值1  像素值2  像素值3  像素值4;

The above four positions are in order: margin-top--margin-right--margin-bottom--margin-left, That is "up-right-down-left". The following abbreviation is top--right--bottom--left. What needs to be noted is that in the latter three cases, when there is a default pixel value, the browser will automatically assign the default pixel according to the "bottom=top" and "left=right" methods.

For example:

"margin:20px;" means the margins in all four directions are 20px;

"margin:20px 40px;" means top is 20px, right is 40px; since bottom and left are default, they are automatically set to 20px and 40px respectively. Converted to the fourth way of writing: "margin:20px 40px 20px 40px;".

"margin:20px 40px 60px;" means top is 20px, right is 40px, and bottom is 60px; since left is default, it is automatically set to 40px. Converted to the fourth writing method: "margin:20px 40px 60px 40px;".

It should be noted that one situation cannot be written as the default writing method: "margin:20px 40px 20px 60px;". In this example, since top and bottom are the same, but right and left are different, bottom cannot be defaulted, otherwise it will be equivalent to "margin:20px 40px 60px 40px;".

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