常用css

/** ie8支持透明度 **/
rgba(0,0,0,0.4);  // 不支持ie8
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#19000000,endColorstr=#19000000);
这个颜色“#19000000”是由两部分组成的。
第一部是#号后面的19 。是rgba透明度0.1的IEfilter值。从0.1到0.9每个数字对应一个IEfilter值。对应关系如下：
0.1 - 19 ； 0.2 - 33 ； 0.3 - 4C ; 0.4 - 66 ; 0.5 - 7F ; 0.6 - 99 ; 0.7 - B2 ; 0.8 - C8 ; 0.9 - E5 ;
 第二部分是19后面的六位 。这个是六进制的颜色值。要跟rgb函数中的取值相同。比如rgb(255,255,255)对应#ffffff；都是白色。
到这里，rgba的用法就可以兼容IE8了。

1、禁止选择文本
body {
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

2、在可打印的网页中显示URLs
@media print   {  
  a:after {  
    content: " [" attr(href) "] ";  
  }  
}

3、深灰色的点击渐变按钮
.graybtn {
    -moz-box-shadow:inset 0px 1px 0px 0px #ffffff;
    -webkit-box-shadow:inset 0px 1px 0px 0px #ffffff;
    box-shadow:inset 0px 1px 0px 0px #ffffff;
    background:-webkit-gradient( linear, left top, left bottom, color-stop(0.05, #ffffff), color-stop(1, #d1d1d1) );
    background:-moz-linear-gradient( center top, #ffffff 5%, #d1d1d1 100% );
    filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#ffffff', endColorstr='#d1d1d1');
    background-color:#ffffff;
    -moz-border-radius:6px;
    -webkit-border-radius:6px;
    border-radius:6px;
    border:1px solid #dcdcdc;
    display:inline-block;
    color:#777777;
    font-family:arial;
    font-size:15px;
    font-weight:bold;
    padding:6px 24px;
    text-decoration:none;
    text-shadow:1px 1px 0px #ffffff;
}
.graybtn:hover {
    background:-webkit-gradient( linear, left top, left bottom, color-stop(0.05, #d1d1d1), color-stop(1, #ffffff) );
    background:-moz-linear-gradient( center top, #d1d1d1 5%, #ffffff 100% );
    filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#d1d1d1', endColorstr='#ffffff');
    background-color:#d1d1d1;
}
.graybtn:active {
    position:relative;
    top:1px;
}


4、网页顶部盒阴影
body:before {
    content: "";
    position: fixed;
    top: -10px;
    left: 0;
    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;
}

5、在可点击的项目上强制手型
a[href], input[type='submit'], input[type='image'], label[for], select, button, .pointer {
    cursor: pointer;
}


6、CSS3 鲜艳的输入（边框渐变）
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;
}

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);
}


7、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- 0.35em 0 0.35em 0.45em;
    display: block;
    height: 0;
    0;
    left: -1em;
    top: 0.9em;
    position: relative;
}


8、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;
}


9、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);
}


10、@font-face模板
@font-face {
    font-family: 'MyWebFont';
    src: url('webfont.eot'); /* IE9 Compat Modes */
    src: url('webfont.eot?#iefix') format('embedded-opentype'), /* IE6-IE8 */
    url('webfont.woff') format('woff'), /* Modern Browsers */
    url('webfont.ttf')  format('truetype'), /* Safari, Android, iOS */
    url('webfont.svg#svgFontName') format('svg'); /* Legacy iOS */
}

body {
    font-family: 'MyWebFont', Arial, sans-serif;
}

11、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);
}

12、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;
}

13、锚链接伪类
a:link { color: blue; }
a:visited { color: purple; }
a:hover { color: red; }
a:active { color: yellow; }

14、图片边框偏光
img.polaroid {
    background:#000; /*Change this to a background image or remove*/
    border:solid #fff;
    border-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*/
    200px; /*Set to width of your image or desired div*/
}

15、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 */
}

16、跨浏览器透明
.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 */
}

17、用CSS动画实现省略号动画
.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 {
        2px;
    }
    to {
        15px;
    }
}

18、制造模糊文本
.blurry-text {
   color: transparent;
   text-shadow: 0 0 5px rgba(0,0,0,0.5);
}

19、包裹长文本    文本过长自动换行不会穿破盒子
pre {
    white-space: pre-line;
    word-wrap: break-word;
}

20、背景渐变色
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;
}

21、内容可编辑（contenteditable="true"）
<ul contenteditable="true">
    <li>悼念遇难香港同胞 </li>
    <li>深圳特区30周年</li>
    <li>伊春空难</li>
</ul>


22、输入框改变placeholder字体颜色
::-webkit-input-placeholder {
  color: red;
}
:-moz-placeholder {
  color: red;
}
::-moz-placeholder{
color: red;
}
:-ms-input-placeholder {
  color: red;
}