问题
I have definitely picked up some useful tips in the hidden features style questions concerning PHP and XHTML.
So here is one to cover CSS. While easy to pick up, it takes a little while to learn about everything, their default behaviors, properties etc
Here are some to start the ball
@charset "UTF-8"; /* set the character set. must be first line as Gumbo points out in comments */
.element {
/* takes precedence over other stylings */
display: block !important;
/* mozilla .... rounded corners with no images */
-moz-border-radius: 10px;
/* webkit equivalent */
-webkit-border-radius: 10px
}
These are not so much hidden, but their use is not often widespread. What tips, tricks, rare features have you discovered with CSS?
回答1:
You can display the document’s title element:
head, title {
display: block;
}
回答2:
Apply multiple styles/classes to an element like this class="bold red GoldBg"
<html><head>
<style>
.bold {font-weight:bold}
.red {color:red}
.GoldBg {background-color:gold}
</style>
</head><body>
<p class="bold red GoldBg">Foo.Bar(red)</p>
</body></html>
回答3:
I really like CSS sprites.
Rather than have 20 images for all your site buttons and logos (and therefore 20 http requests with the latency around each one) you just use one image, and position it each time so only the bit you want is visible.
It's difficult to post an example as you'd need to see the component image and the placement CSS - but I've blogged Google's use of it here: http://www.stevefenton.co.uk/Content/Blog/Date/200905/Blog/Google-Uses-Image-Sprites/
回答4:
The fact that floating a parent element will cause it to expand to contain all of its floated children.
回答5:
Maybe negative margins and absolute positioned elements in relative positioned elements.
See How would YOU do this with CSS? for examples.
回答6:
You can set a variable width for an absolutely positioned element by specifying both left and right properties. This gives you more control than simply setting width to a percentage.
For example:
#myElement {
position: absolute;
left: 5px;
right: 10px;
}
An alternative Example
#myElement{ /* fill up the whole space :) */
background: red;
position:absolute;
left: 0;
right:0;
top: 0;
bottom: 0;
}
回答7:
Take a look at Webkit CSS Transformations, e.g. -webkit-transform: rotate(9deg);
回答8:
My ones are:
- all properties of aural sheets like
azimuth,pitch... - some properties of the print module like
page-break-after: avoid; counter-increment: section 1;border-collapse: collapse;background-color: transparent;outline: 1px solid...
回答9:
Not really a feature, but useful nonetheless: The child selector works in all browsers except IE6, allowing you to isolate IE6 without using hacks or conditional stylesheets or invalidating your code. Thus, the link in the following code will be red in IE6, blue in every other browser.
CSS
/*Red for IE6*/
.link {color:#F00;}
/*Blue for everything else*/
#content>.link {color:#00F;}
HTML
<div id="content">
<a class="link" href="#">Link</a>
</div>
Here is a list of selectors (for CSS2) and a browser compatibility chart.
回答10:
Last week I came across an amazingly useful CSS property I had never heard of:
text-rendering: optimizeLegibility;
Safari, Chrome and Firefox all understand this property, and when set enable advanced kerning and ligatures. Here's a great demo.
回答11:
Transparent PNG in IE6 This fixes PNG transparency in IE6. Set background to non and include the image in filter. No need for any javascript or htc.
.whatever {
background: none; /* Hide the current background image so you can replace it with the filter*/
width: 500px; /* Must specify width */
height: 176px; /* Must specify height */
filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, sizingMethod=scale, src='vehicles.png');
}
Sets page-breaking behavior after an element - Cross browser
table {
page-break-after:always
}
You can use the properties always, avoid, auto, left, right, inherent. Read docs at http://www.w3schools.com/CSS/pr_print_pageba.asp
A way to number sections and sub-sections with "Section 1", "1.1", "1.2", etc - Cross browser
h2:before
{
counter-increment:subsection;
content:counter(section) "." counter(subsection) " ";
}
http://www.w3schools.com/CSS/pr_gen_counter-increment.asp
Collapse Table borders into a single border or detached as in standard HTML - Cross browser
table
{
border-collapse:collapse;
}
http://www.w3schools.com/css/pr_tab_border-collapse.asp
Remove selection Border or dotted line from button or input fields. Has other great uses - Cross browser
button{
outline:0;
}
http://www.w3schools.com/CSS/pr_outline.asp
* html for 100% height in IE6
* html .move{
height:100%;
}
Allow long words to break and wrap onto the next line - CSS3 Cross browser
.whatever {
word-wrap:break-word;
}
http://www.w3schools.com/css3/css3_pr_word-wrap.asp
Shorthands
Before
font-size: 1em;
line-height: 1.5em;
font-weight: bold;
font-style: italic;
font-family: serif
After
font: 1em/1.5em bold italic serif;
Before
background-color: #fff;
background-image: url(image.gif);
background-repeat: no-repeat;
background-position: top left;
After
background: #fff url(image.gif) no-repeat top left;
Before
list-style: #fff;
list-style-type: disc;
list-style-position: outside;
list-style-image: url(image.gif)
After
list-style: disc outside url(something.gif);
Before
margin-top: 2px;
margin-right: 1px;
margin-bottom: 3px;
margin-left: 4px
After
margin:2px 1px 3px 4px; /*also works for padding*/
margin:0; /*You can also do this for all 0 borders*/
margin:2px 3px 5px; /* you can do this for top 2px, left/right 3px, bottom 5px and ;
回答12:
You can create scrolling areas without resorting to frames by using CSS's overflow property. Example:
div.foo {
border: 1px solid;
width: 300px;
height: 300px;
overflow: auto;
}
overflow: auto means if the content can't fit within the div, horizontal and/or vertical scroll bars will appear as needed.
overflow: scroll means both scroll bars will always be present. If you only want one scroll bar to always be present, use overflow-x or overflow-y (which are supported by modern browsers and IE6).
Some of you may be thinking "duuuh", but I was surprised to learn that scrolling areas can be created without frames.
回答13:
The :before and :after pseudo-elements
The following rule causes the string "Chapter: " to be generated before each H1 element:
H1:before {
content: "Chapter: ";
display: inline;
}
For more, http://www.w3.org/TR/CSS2/generate.html
回答14:
Not so much hidden features, but a question featuring CSS tips which every beginning developer should know about
回答15:
inline blocks (alternative to floating divs):
.inline_block
{
display:-moz-inline-box;
display:inline-block;
}
Don't apply this class to a div! it won't work! apply it to a span (or an inline element)
<span class="inline_block">
</span>
回答16:
Inline @media assignments:
/* Styles.css */
.foo { ... bar ... }
...
@media print{
.ads{display:none}
}
So that you can get rid of another HTTP request.
回答17:
We can display the style tag as a block element and edit CSS dynamically using the HTML5 contenteditable attribute. Demo Here.
<body>
<style contenteditable>
style {
display: block;
}
body {
background: #FEA;
}
</style>
</body>
Credits: CSS-Tricks
回答18:
Not really "hidden", but understanding the box model and positioning model will help tremendously.
Like, knowing that a position: absolute element is positioned relative to its first parent that is styled with position: relative.
回答19:
Currently only for WebKit but quite interesting: CSS Animations
回答20:
I have never thought that using css 'border' property I can make different shaped triangle. Here is the link to go,
(edit) The following link does not work anymore. http://www.dinnermint.org/blog/css/creating-triangles-in-css/
From now, you can try the following, http://jonrohan.me/guide/css/creating-triangles-in-css/
回答21:
Word wrapping can be done easily using css, without any help of server-side technology.
word-wrap: break-word;
回答22:
Another IE6 selector
* html .something
{
color:red;
}
Fixing random IE6 rendering bugs - apply zoom:1 which will trigger layout.
回答23:
Cross-browser (IE6+, FF, Safari) float alternative:
.inline-block {
display: inline-block;
display: -moz-inline-box;
-moz-box-orient: vertical;
vertical-align: top;
zoom: 1;
*display: inline; }
回答24:
Cross browser inline-block works on block and inline elements using the combined declarations:
.column {
-moz-inline-box; -moz-box-orient:vertical; display:inline-block; vertical-align:top;
}
for standards browsers including Firefox 2, and:
.ie_lte7 .column { display:inline; }
回答25:
I have no Idea whether this is a hidden feature, but I just wowed seeing this: http://www.romancortes.com/blog/css-3d-meninas/
回答26:
.class {
/* red for chrome, ff, safari, opera */
background-color: red;
/* green for IE6 */
.background-color: green;
/* blue for IE7+ */
_background-color: blue;
}
will render your <whatever> background different in those browser categories
回答27:
The border-radius stuff is part of the CSS3 specification. As CSS3 is still not completely finished the more progressive browsers in the meantime implement parts of it with their own properties (-moz, -webkit). So we can already enjoy rounded corners, cleanly coded in pure css.
Unfortunately the other big player in the browser market still shows no sign of implementing css3 features.
来源：https://stackoverflow.com/questions/628407/hidden-features-of-css