Several commonly used classic CSS techniques_Experience exchange

Use line-height for vertical centering

line-height:24px;
When using a fixed-width container and need a row to be vertically centered, use line-height (the height is the same as the parent layer container) , more vertical centering summary can be seen here.

Clear container floats

#main {
overflow:hidden;
}
Such a problem was also mentioned before. For more information, you can see here.

Do not allow links to wrap

a {
white-space:nowrap;
}
The above settings can prevent links from wrapping, but I personally recommend long The link will have the corresponding line (for a discussion of line breaks, see the record in the center of the circle).

Always let Firefox display scroll bars

html {
overflow:-moz-scrollbars-vertical;
}
For more Mozilla/Firefox private CSS properties, please refer to here. For cross-browser support, you can also use

body, html {
min-height:101%;
}
Center the block element horizontally

margin: 0 auto;
In fact, it is

margin-left: auto;
margin-right: auto;
Basically all CSS textbooks will explain this technique, don’t forget to add it width. You can also use

body{
text-align: center;
}
and then define the inner container

text-align: left;
Restore .

Hide the scroll bar of the Explorer textarea

textarea {
overflow:auto;
}
Exploer textarea has vertical scroll bars by default (don’t ask me why) .

Set printing paging

h2 {
page-break-before:always;
}
page-break-before attribute can set paging when printing web pages.

Remove the dotted box on the link

a:active, a:focus {
outline:none;
}
Firefox will focus on the link by default (or click ), add a dotted frame, which can be deleted using the properties above.

The simplest CSS reset

* {
margin: 0; padding: 0
}
If you want to be "complex", refer to YUI's approach (and here). Some users also expressed their opinions in the original message

I have to agree with Niall Doherty, * {margin: 0px; padding: 0px;}
basically means "traverse every css element and give it these attributes". That is a very unnecessary strain on the server and
a bad semantic practice, as you have to give some elements
padding/margin again, after stripping them.