How to set the border of DIV + CSS webpage layout

CSS Borders border
The border can be applied to most HTML elements in the body.
To create an element border, you need the border-style border style. The values can be: solid, dotted, dashed, double, groove, ridge, inset and outset.
Border-width is used to set the width. pixels is usually used, that is, the unit is px. It also has the four-side attribute: border-top-width, border-right-width, border-bottom-width and border-left-width.
Border-color: specifies the border color.
Example

The code is as follows:	Copy code
H2 { Border-style: dashed; Border-width: 3px; Border-left-width: 10px; Border-right-width: 10px; Border-color: red; }

Set the red style to the dashed border, the upper and lower border width to 3px, and the left and right to 10px (the subsequent attributes overwrite the front ).