CSS outline

The properties involved are:

outline Set all outline properties in one statement.

outline-color Set the color of the outline.

outline-style Set the style of the outline.

outline-width Set the width of the outline.

In order to demonstrate, we first add two p tags to the original html:

This is some text in a paragraph.
 
This is some text in a paragraph.

Then add the specific settings of these attributes in CSS. The setting parameters will not be elaborated too much:

    
  
This is some text in a paragraph.
 
This is some text in a paragraph.
 
注释：只有在规定了 !DOCTYPE 时，Internet Explorer 8 （以及更高版本） 才支持 outline-width 属性。
  

The following is the rendering:

CSS border property

in the "CSS" column The number indicates which CSS version defines the property.