css的一些常用小技巧

1.增加一个小箭头,tip

	<i class="arrow arrow-out"></i>
	<i class="arrow arrow-in"></i>

.appmsg-edit .arrow {
position: absolute;
}

.appmsg-edit .arrow-out {
 border-top: 12px dashed transparent;
border-right: 12px solid #F8F8F8;
border-bottom: 12px dashed transparent;
border-left: 0 dashed transparent;
display: inline-block;
height: 0;
left: 0;
top: 44px;
width: 0;
}

.appmsg-edit .arrow-in {
border-top: 12px dashed transparent;
border-right: 12px solid #F8F8F8;
border-bottom: 12px dashed transparent;
border-left: 0 dashed transparent;
display: inline-block;
height: 0;
left: 1px;
top: 44px;
width: 0;
} ##2.两个div对齐，左边的div没有数据，有背景色,需要跟右边对齐

父div:
overflow:hidden

左边和右边的div:
margin-bottom: -3888px;
padding-bottom: 3888px;

3.万能清除浮动

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

.clearfix {
zoom: 1;
} ##4.处理父元素里面的空白
	white-space: nowrap; ##5.设置透明
rgba(0,0,0,0)//完全透明---------ie下不识别
transparent----------------都可以识别
opacity-----------------------标准浏览器识别，ie下不识别，opacity是0-1
filter:Alpha(opacity=0)-------ie下可以识别，opacity是0-100，step是10
opacity是0是看不到的，1是看得到的

6.ie6/7下设置select的的高度和边框


.select-box{
    *padding: 10px 10px 10px 0px;
    *width: 180px;
    *border: 1px solid #ccc;
    *background: #fff;
    display: inline-block;
    *display: inline;
    zoom:1;
}
.select-wrap{
 *width: 190px;
    *height: 19px;
    *line-height: 16px;
    *overflow: hidden;
    display: inline-block;
    *display: inline;
    overflow:hidden;
    position: relative;
    zoom:1;
}
.select-wrap select{
    *margin: -1px;
    *width: 192px;
    *height: 21px;
    *font-size:12px;
    *overflow: hidden;
    *display: block;
    zoom:1;
    position: relative;
}