Accumulation of css style usage_html/css_WEB-ITnose

Let’s look at the example directly and then explain the usage.

I am Donald Duck.

I live in Duckburg.

Note: For :before to work in IE8, a DOCTYPE must be declared.

The page effect is displayed as follows:

Let’s explain the use of the following css writing method

input[type="checkbox"] p:before{
content:"Lines:";
}

It only The two words "lines" will be added to the first paragraph with the label p immediately after the checkbox. There is a usage of and: before here, which is understood as the meaning of and, that is, input[type= "checkbox"] and the style will be added to the first p