CSS Elementary tutorial border

The border can be applied to most HTML elements in the body of the body element.
Create a border surrounded by elements. What you need is the border style border-style. Their values can be solid, dotted, dashed, double, groove, ridge, inset, and outset. (You need to try each value to see how it works)
Border width border-width indicates the border width, which is usually expressed in pixels. Of course, you can also set border attributes in four directions separately, which are border-top-width, border-right-width, border-bottom-width, and border-left-width.
Finally, set the border color border-color.
Add the following code for the following CSS document:

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; }

This will generate a red dashed border for all HTML second-level titles (h2) with three pixels in width up and down, the left and right sides are each 10 pixels wide (instead of the 3 pixel wide global setting ).
About the box model