CSS缩写语法

<style type="text/css">
<!--
.t1 {
padding-top: 3px;
padding-right: 20px;
padding-bottom: 3px;
padding-left: 20px;
}
.t2 {
padding: 3px 20px 3px 20px;
}
.t3 {
padding: 3px 20px 3px;
}
.t4 {
padding: 3px 20px;
}
span {
border: 1px solid #CCCCCC;
}
-->
</style>
<span class="t1">cnbruce</span>
<span class="t2">cnrose</span>
<span class="t3">cnjames</span>
<span class="t4">www.cnbruce.com</span>