/* 禁止选中文本 */
.usn{
-webkit-user-select:none;
-moz-user-select:none;
-ms-user-select:none;
-o-user-select:none;
user-select:none;
}
/* 浮动 */
.fl { float: left; }
.fr { float: right; }
.cf { zoom: 1; }
.cf:after {
content:".";
display:block;
clear:both;
visibility:hidden;
height:0;
overflow:hidden;
}
/* 元素类型 */
.db { display: block; }
.dn { display: none; }
.di { display: inline }
.dib {display: inline-block;}
.transparent { opacity: 0 }
/*文字排版、颜色*/
.f12 { font-size:12px }
.f14 { font-size:14px }
.f16 { font-size:16px }
.f18 { font-size:18px }
.f20 { font-size:20px }
.fb { font-weight:bold }
.fn {