有用的css片段

1、背景渐变动画

CSS中最具诱惑的一个功能是能添加动画效果，除了渐变，你可以给背景色、透明度、元素大小添加动画。目前，你不能为渐变添加动画，但下面的代码可能有帮助。它通过改变背景位置，让它看起来有动画效果。

button {
    background-image: linear-gradient(#5187c4, #1c2f45);
    background-size: auto 200%;
    background-position: 0 100%;
    transition: background-position 0.5s;
}
button:hover {
    background-position: 0 0;
}

2、只在一边或两边显示盒子阴影

如果你要一个盒阴影，试试这个技巧，能为任一边添加阴影。为了实现这个，首先定义一个有具体宽高的盒子，然后正确定位:after伪类。实现底边阴影的代码如下：

.box-shadow {
    background-color: #FF8020;
    width: 160px;
    height: 90px;
    margin-top: -45px;
    margin-left: -80px;
    position: absolute;
    top: 50%;
    left: 50%;
}
.box-shadow:after {
    content: "";
    width: 150px;
    height: 1px;
    margin-top: 88px;
    margin-left: -75px;
    display: block;
    position: absolute;
    left: 50%;
    z-index: -1;
    -webkit-box-shadow: 0px 0px 8px 2px #000000;
       -moz-box-shadow: 0px 0px 8px 2px #000000;
            box-shadow: 0px 0px 8px 2px #000000;
}

3、包裹长文本

如果你碰到一个比自身容器长的文本，这个技巧对你很有用。在这个示例中，默认时，不管容器的宽度，文本都将水平填充。
 简单的CSS代码就能在容器中调整文本：

pre {
    white-space: pre-line;
    word-wrap: break-word;
}

效果看起来如下：

4、制造模糊文本

想要让文本模糊？可以使用color透明和text-shadow实现。

 

.blurry-text {
   color: transparent;
   text-shadow: 0 0 5px rgba(0,0,0,0.5);
}

5、用CSS动画实现省略号动画

这个片段将帮助你制造一个ellipsis的动画，对于简单的加载状态是很有用的，而不用去使用gif图像。

 

.loading:after {
    overflow: hidden;
    display: inline-block;
    vertical-align: bottom;
    animation: ellipsis 2s infinite;
    content: "\2026"; /* ascii code for the ellipsis character */
}
@keyframes ellipsis {
    from {
        width: 2px;
    }
    to {
        width: 15px;
    }
}

6、样式重置

html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video {
  margin: 0;
  padding: 0;
  border: 0;
  font-size: 100%;
  font: inherit;
  vertical-align: baseline;
  outline: none;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
html { height: 101%; }
body { font-size: 62.5%; line-height: 1; font-family: Arial, Tahoma, sans-serif; }

article, aside, details, figcaption, figure, footer, header, hgroup, menu, nav, section { display: block; }
ol, ul { list-style: none; }

blockquote, q { quotes: none; }
blockquote:before, blockquote:after, q:before, q:after { content: ''; content: none; }
strong { font-weight: bold; } 

table { border-collapse: collapse; border-spacing: 0; }
img { border: 0; max-width: 100%; }

p { font-size: 1.2em; line-height: 1.0em; color: #333; }

 

7、典型的CSS清除浮动

.clearfix:after { content: "."; display: block; clear: both; visibility: hidden; line-height: 0; height: 0; }
.clearfix { display: inline-block; }

html[xmlns] .clearfix { display: block; }
* html .clearfix { height: 1%; }

8、新版清除浮动（2011）

 

.clearfix:before, .container:after { content: ""; display: table; }
.clearfix:after { clear: both; }

/* IE 6/7 */
.clearfix { zoom: 1; }

9、跨浏览器的透明

 

.transparent {
    filter: alpha(opacity=50); /* internet explorer */
    -khtml-opacity: 0.5;      /* khtml, old safari */
    -moz-opacity: 0.5;       /* mozilla, netscape */
    opacity: 0.5;           /* fx, safari, opera */
}

10、个性圆角

 

#container {
    -webkit-border-radius: 4px 3px 6px 10px;
    -moz-border-radius: 4px 3px 6px 10px;
    -o-border-radius: 4px 3px 6px 10px;
    border-radius: 4px 3px 6px 10px;
}

/* alternative syntax broken into each line */
#container {
    -webkit-border-top-left-radius: 4px;
    -webkit-border-top-right-radius: 3px;
    -webkit-border-bottom-right-radius: 6px;
    -webkit-border-bottom-left-radius: 10px;

    -moz-border-radius-topleft: 4px;
    -moz-border-radius-topright: 3px;
    -moz-border-radius-bottomright: 6px;
    -moz-border-radius-bottomleft: 10px;
}

11、通用媒体查询

/* Smartphones (portrait and landscape) ----------- */
@media only screen
and (min-device-width : 320px) and (max-device-width : 480px) {
  /* Styles */
}

/* Smartphones (landscape) ----------- */
@media only screen and (min-width : 321px) {
  /* Styles */
}

/* Smartphones (portrait) ----------- */
@media only screen and (max-width : 320px) {
  /* Styles */
}

/* iPads (portrait and landscape) ----------- */
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) {
  /* Styles */
}

/* iPads (landscape) ----------- */
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : landscape) {
  /* Styles */
}

/* iPads (portrait) ----------- */
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : portrait) {
  /* Styles */
}

/* Desktops and laptops ----------- */
@media only screen and (min-width : 1224px) {
  /* Styles */
}

/* Large screens ----------- */
@media only screen and (min-width : 1824px) {
  /* Styles */
}

/* iPhone 4 ----------- */
@media only screen and (-webkit-min-device-pixel-ratio:1.5), only screen and (min-device-pixel-ratio:1.5) {
  /* Styles */
}

12、现代字体栈

/* Times New Roman-based serif */
font-family: Cambria, "Hoefler Text", Utopia, "Liberation Serif", "Nimbus Roman No9 L Regular", Times, "Times New Roman", serif;

/* A modern Georgia-based serif */
font-family: Constantia, "Lucida Bright", Lucidabright, "Lucida Serif", Lucida, "DejaVu Serif," "Bitstream Vera Serif", "Liberation Serif", Georgia, serif;

/*A more traditional Garamond-based serif */
font-family: "Palatino Linotype", Palatino, Palladio, "URW Palladio L", "Book Antiqua", Baskerville, "Bookman Old Style", "Bitstream Charter", "Nimbus Roman No9 L", Garamond, "Apple Garamond", "ITC Garamond Narrow", "New Century Schoolbook", "Century Schoolbook", "Century Schoolbook L", Georgia, serif;

/*The Helvetica/Arial-based sans serif */
font-family: Frutiger, "Frutiger Linotype", Univers, Calibri, "Gill Sans", "Gill Sans MT", "Myriad Pro", Myriad, "DejaVu Sans Condensed", "Liberation Sans", "Nimbus Sans L", Tahoma, Geneva, "Helvetica Neue", Helvetica, Arial, sans-serif;

/*The Verdana-based sans serif */
font-family: Corbel, "Lucida Grande", "Lucida Sans Unicode", "Lucida Sans", "DejaVu Sans", "Bitstream Vera Sans", "Liberation Sans", Verdana, "Verdana Ref", sans-serif;

/*The Trebuchet-based sans serif */
font-family: "Segoe UI", Candara, "Bitstream Vera Sans", "DejaVu Sans", "Bitstream Vera Sans", "Trebuchet MS", Verdana, "Verdana Ref", sans-serif;

/*The heavier "Impact" sans serif */
font-family: Impact, Haettenschweiler, "Franklin Gothic Bold", Charcoal, "Helvetica Inserat", "Bitstream Vera Sans Bold", "Arial Black", sans-serif;

/*The monospace */
font-family: Consolas, "Andale Mono WT", "Andale Mono", "Lucida Console", "Lucida Sans Typewriter", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Liberation Mono", "Nimbus Mono L", Monaco, "Courier New", Courier, monospace;

 

13、自定义文本选择

 

::selection { background: #e2eae2; }
::-moz-selection { background: #e2eae2; }
::-webkit-selection { background: #e2eae2; }

14、为logo隐藏H1

h1 {
    text-indent: -9999px;
    margin: 0 auto;
    width: 320px;
    height: 85px;
    background: transparent url("images/logo.png") no-repeat scroll;
}

 

15、图片边框偏光

 

img.polaroid {
    background:#000; /*Change this to a background image or remove*/
    border:solid #fff;
    border-width:6px 6px 20px 6px;
    box-shadow:1px 1px 5px #333; /* Standard blur at 5px. Increase for more depth */
    -webkit-box-shadow:1px 1px 5px #333;
    -moz-box-shadow:1px 1px 5px #333;
    height:200px; /*Set to height of your image or desired div*/
    width:200px; /*Set to width of your image or desired div*/
}

16、锚链接伪类

 

a:link { color: blue; }
a:visited { color: purple; }
a:hover { color: red; }
a:active { color: yellow; }

17、CSS3：全屏背景

 

html {
    background: url('images/bg.jpg') no-repeat center center fixed;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}

18、内容垂直居中

 

.container {
    min-height: 6.5em;
    display: table-cell;
    vertical-align: middle;
}

19、强制出现垂直滚动条

 

html { height: 101% }

20、CSS3渐变模板

 

#colorbox {
    background: #629721;
    background-image: -webkit-gradient(linear, left top, left bottom, from(#83b842), to(#629721));
    background-image: -webkit-linear-gradient(top, #83b842, #629721);
    background-image: -moz-linear-gradient(top, #83b842, #629721);
    background-image: -ms-linear-gradient(top, #83b842, #629721);
    background-image: -o-linear-gradient(top, #83b842, #629721);
    background-image: linear-gradient(top, #83b842, #629721);
}

21、缝合CSS3元素

p {
    position:relative;
    z-index:1;
    padding: 10px;
    margin: 10px;
    font-size: 21px;
    line-height: 1.3em;
    color: #fff;
    background: #ff0030;
    -webkit-box-shadow: 0 0 0 4px #ff0030, 2px 1px 4px 4px rgba(10,10,0,.5);
    -moz-box-shadow: 0 0 0 4px #ff0030, 2px 1px 4px 4px rgba(10,10,0,.5);
    box-shadow: 0 0 0 4px #ff0030, 2px 1px 6px 4px rgba(10,10,0,.5);
    -webkit-border-radius: 3px;
    -moz-border-radius: 3px;
    border-radius: 3px;
}

p:before {
    content: "";
    position: absolute;
    z-index: -1;
    top: 3px;
    bottom: 3px;
    left :3px;
    right: 3px;
    border: 2px dashed #fff;
}

p a {
    color: #fff;
    text-decoration:none;
}

p a:hover, p a:focus, p a:active {
    text-decoration:underline;
}

22、CSS3 斑马线

 

tbody tr:nth-child(odd) {
    background-color: #ccc;
}

23、有趣的&

 

.amp {
    font-family: Baskerville, 'Goudy Old Style', Palatino, 'Book Antiqua', serif;
    font-style: italic;
    font-weight: normal;
}

24、大字段落

 

p:first-letter{
    display: block;
    margin: 5px 0 0 5px;
    float: left;
    color: #ff3366;
    font-size: 5.4em;
    font-family: Georgia, Times New Roman, serif;
}

25、内部CSS3 盒阴影

#mydiv {
    -moz-box-shadow: inset 2px 0 4px #000;
    -webkit-box-shadow: inset 2px 0 4px #000;
    box-shadow: inset 2px 0 4px #000;
}

26、外部CSS3 盒阴影

 

#mydiv {
    -webkit-box-shadow: 0 2px 2px -2px rgba(0, 0, 0, 0.52);
    -moz-box-shadow: 0 2px 2px -2px rgba(0, 0, 0, 0.52);
    box-shadow: 0 2px 2px -2px rgba(0, 0, 0, 0.52);
}

27、三角形列表项目符号

ul {
    margin: 0.75em 0;
    padding: 0 1em;
    list-style: none;
}
li:before {
    content: "";
    border-color: transparent #111;
    border-style: solid;
    border-width: 0.35em 0 0.35em 0.45em;
    display: block;
    height: 0;
    width: 0;
    left: -1em;
    top: 0.9em;
    position: relative;
}

 

28、CSS3 列文本

 

#columns-3 {
    text-align: justify;
    -moz-column-count: 3;
    -moz-column-gap: 12px;
    -moz-column-rule: 1px solid #c4c8cc;
    -webkit-column-count: 3;
    -webkit-column-gap: 12px;
    -webkit-column-rule: 1px solid #c4c8cc;
}

29、IE6的PNG透明修复

 

.bg {
    width:200px;
    height:100px;
    background: url(/folder/yourimage.png) no-repeat;
    _background:none;
    _filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='/folder/yourimage.png',sizingMethod='crop');
}

/* 1px gif method */
img, .png {
    position: relative;
    behavior: expression((this.runtimeStyle.behavior="none")&&(this.pngSet?this.pngSet=true:(this.nodeName == "IMG" && this.src.toLowerCase().indexOf('.png')>-1?(this.runtimeStyle.backgroundImage = "none",
       this.runtimeStyle.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + this.src + "', sizingMethod='image')",
       this.src = "images/transparent.gif"):(this.origBg = this.origBg? this.origBg :this.currentStyle.backgroundImage.toString().replace('url("','').replace('")',''),
       this.runtimeStyle.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + this.origBg + "', sizingMethod='crop')",
       this.runtimeStyle.backgroundImage = "none")),this.pngSet=true));
}

30、跨浏览器设置最小高度

 

#container {
    min-height: 550px;
    height: auto !important;
    height: 550px;
}

31、CSS3 鲜艳的输入

 

input[type=text], textarea {
    -webkit-transition: all 0.30s ease-in-out;
    -moz-transition: all 0.30s ease-in-out;
    -ms-transition: all 0.30s ease-in-out;
    -o-transition: all 0.30s ease-in-out;
    outline: none;
    padding: 3px 0px 3px 3px;
    margin: 5px 1px 3px 0px;
    border: 1px solid #ddd;
}

32、基于文件类型的链接样式

 

/* external links */
a[href^="http://"] {
    padding-right: 13px;
    background: url('external.gif') no-repeat center right;
}

/* emails */
a[href^="mailto:"] {
    padding-right: 20px;
    background: url('email.png') no-repeat center right;
}

/* pdfs */
a[href$=".pdf"] {
    padding-right: 18px;
    background: url('acrobat.png') no-repeat center right;
}

input[type=text]:focus, textarea:focus { box-shadow: 0 0 5px rgba(81, 203, 238, 1); padding: 3px 0px 3px 3px; margin: 5px 1px 3px 0px; border: 1px solid rgba(81, 203, 238, 1); }

33、强制换行

pre {
    white-space: pre-wrap;       /* css-3 */
    white-space: -moz-pre-wrap;  /* Mozilla, since 1999 */
    white-space: -pre-wrap;      /* Opera 4-6 */
    white-space: -o-pre-wrap;    /* Opera 7 */
    word-wrap: break-word;       /* Internet Explorer 5.5+ */
}

 

34、网页顶部盒阴影

 

body:before {
    content: "";
    position: fixed;
    top: -10px;
    left: 0;
    width: 100%;
    height: 10px;

    -webkit-box-shadow: 0px 0px 10px rgba(0,0,0,.8);
    -moz-box-shadow: 0px 0px 10px rgba(0,0,0,.8);
    box-shadow: 0px 0px 10px rgba(0,0,0,.8);
    z-index: 100;
}

35、纯CSS背景噪音

 

body {
    background-image: url(data:image/png;base64,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);
    background-color: #0094d0;
}

36、持久的列表排序

 

ol.chapters {
    list-style: none;
    margin-left: 0;
}

ol.chapters > li:before {
    content: counter(chapter) ". ";
    counter-increment: chapter;
    font-weight: bold;
    float: left;
    width: 40px;
}

ol.chapters li {
    clear: left;
}

ol.start {
    counter-reset: chapter;
}

ol.continue {
    counter-reset: chapter 11;
}

37、CSS悬浮提示文本

a {
    border-bottom:1px solid #bbb;
    color:#666;
    display:inline-block;
    position:relative;
    text-decoration:none;
}
a:hover,
a:focus {
    color:#36c;
}
a:active {
    top:1px;
}

/* Tooltip styling */
a[data-tooltip]:after {
    border-top: 8px solid #222;
    border-top: 8px solid hsla(0,0%,0%,.85);
    border-left: 8px solid transparent;
    border-right: 8px solid transparent;
    content: "";
    display: none;
    height: 0;
    width: 0;
    left: 25%;
    position: absolute;
}
a[data-tooltip]:before {
    background: #222;
    background: hsla(0,0%,0%,.85);
    color: #f6f6f6;
    content: attr(data-tooltip);
    display: none;
    font-family: sans-serif;
    font-size: 14px;
    height: 32px;
    left: 0;
    line-height: 32px;
    padding: 0 15px;
    position: absolute;
    text-shadow: 0 1px 1px hsla(0,0%,0%,1);
    white-space: nowrap;
    -webkit-border-radius: 5px;
    -moz-border-radius: 5px;
    -o-border-radius: 5px;
    border-radius: 5px;
}
a[data-tooltip]:hover:after {
    display: block;
    top: -9px;
}
a[data-tooltip]:hover:before {
    display: block;
    top: -41px;
}
a[data-tooltip]:active:after {
    top: -10px;
}
a[data-tooltip]:active:before {
    top: -42px;
}

38、禁用移动Webkit的选择高亮

 

body {
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

 

39、CSS3 圆点图案

 

body {
    background: radial-gradient(circle, white 10%, transparent 10%),
    radial-gradient(circle, white 10%, black 10%) 50px 50px;
    background-size: 100px 100px;
}

40、CSS3 方格图案

 

body {
    background-color: white;
    background-image: linear-gradient(45deg, black 25%, transparent 25%, transparent 75%, black 75%, black),
    linear-gradient(45deg, black 25%, transparent 25%, transparent 75%, black 75%, black);
    background-size: 100px 100px;
    background-position: 0 0, 50px 50px;
}

41、论文页面的卷曲效果

ul.box {
    position: relative;
    z-index: 1; /* prevent shadows falling behind containers with backgrounds */
    overflow: hidden;
    list-style: none;
    margin: 0;
    padding: 0;
}

ul.box li {
    position: relative;
    float: left;
    width: 250px;
    height: 150px;
    padding: 0;
    border: 1px solid #efefef;
    margin: 0 30px 30px 0;
    background: #fff;
    -webkit-box-shadow: 0 1px 4px rgba(0, 0, 0, 0.27), 0 0 40px rgba(0, 0, 0, 0.06) inset;
    -moz-box-shadow: 0 1px 4px rgba(0, 0, 0, 0.27), 0 0 40px rgba(0, 0, 0, 0.06) inset;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.27), 0 0 40px rgba(0, 0, 0, 0.06) inset;
}

ul.box li:before,
ul.box li:after {
    content: '';
    z-index: -1;
    position: absolute;
    left: 10px;
    bottom: 10px;
    width: 70%;
    max-width: 300px; /* avoid rotation causing ugly appearance at large container widths */
    max-height: 100px;
    height: 55%;
    -webkit-box-shadow: 0 8px 16px rgba(0, 0, 0, 0.3);
    -moz-box-shadow: 0 8px 16px rgba(0, 0, 0, 0.3);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.3);
    -webkit-transform: skew(-15deg) rotate(-6deg);
    -moz-transform: skew(-15deg) rotate(-6deg);
    -ms-transform: skew(-15deg) rotate(-6deg);
    -o-transform: skew(-15deg) rotate(-6deg);
    transform: skew(-15deg) rotate(-6deg);
}

ul.box li:after {
    left: auto;
    right: 10px;
    -webkit-transform: skew(15deg) rotate(6deg);
    -moz-transform: skew(15deg) rotate(6deg);
    -ms-transform: skew(15deg) rotate(6deg);
    -o-transform: skew(15deg) rotate(6deg);
    transform: skew(15deg) rotate(6deg);
}

42、带CSS3特色的横幅显示

.featureBanner {
    position: relative;
    margin: 20px
}
.featureBanner:before {
    content: "Featured";
    position: absolute;
    top: 5px;
    left: -8px;
    padding-right: 10px;
    color: #232323;
    font-weight: bold;
    height: 0px;
    border: 15px solid #ffa200;
    border-right-color: transparent;
    line-height: 0px;
    box-shadow: -0px 5px 5px -5px #000;
    z-index: 1;
}

.featureBanner:after {
    content: "";
    position: absolute;
    top: 35px;
    left: -8px;
    border: 4px solid #89540c;
    border-left-color: transparent;
    border-bottom-color: transparent;
}

43.最后一个li不加border－right

nav li:not(:last-child){
　　border-right:1px solid #666;
}

44.垂直居中任何元素

html, body {
  height: 100%;
  margin: 0;
}

body {
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  display: -webkit-flex;
  display: flex;
}

45.使用负的 nth-child 来选择元素

   使用负的 可以选择 1 至 n 个元素。

   让1-3的元素显示出来

   li { display :none ; }

   li:nth-child(-n+3){display:block; }

   或者

   li:not:nth-child(-n+3){ display:none; }

 

46.形似“猫头鹰”的选择器

除首个元素外，其他的兄弟元素都加上间距

＊＋＊｛margin－top：1.5em;}