1. Vertical centering with line-height
line-height:24px;
When you have a container with fixed height you can use line-height property to vertically center the content.
Take a look at this demo.
2. Prevent oversized content to break fixed width floated layouts
#main{
overflow:hidden;
}
When oversized content (i.e. wide image) is placed in fixed width floated container, it may break the layout. To prevent that use this trick. It will hide a part of the content but at least your layout structure will remain intact.
I wrote an article about it a while back.
3. Prevent line breaks in links
a{
white-space:nowrap;
}
This little trick will prevent line breaks on your links. I recommend using this with long text to avoid having links break into 2 lines.
4. Always show Firefox scrollbar
html{
overflow:-moz-scrollbars-vertical;
}
Firefox hides vertical scrollbar by default. So, when you browse a site that have different page heights you notice a horizontal shift. This code will always display a scrollbar and prevent shifting.
5. Centering block elements horizontally
margin:0 auto;
For all modern browser this line of css is enough to horizontally center a block level element.
6. Remove vertical textarea scrollbar in IE
textarea{
overflow:auto;
}
Textareas in IE have vertical scrollbar visible by default. If you want those removed (I know I do) use this line.
7. Force page breaks when printing your document
h2{
page-break-before:always;
}
With this line of code you can control places where you want your pages to break when printing a document.
8. Remove active link borders
a:active, a:focus{
outline:none;
}
Originally found here, this will remove dotted outline from focused or active links.
中文版：几个经典的css技巧