text-indent:-9999px;什么意思.

text-indent:-9999px;什么意思. text-indent: css属性,text-indent: css中“text-indent： 请问 text-indent:2em text-indent:0.9em; 是什么意思? 帮看看这段代码是什么意思.jysdfecss{width:5px; height:5px; clear:both; text-indent:10px;}.jyyksdf{margin:5px; padding:0; overflow:hidden;}.jycsdfe{width:5px; height:5px; clear:both; text-indent:10px;}.jyvcbodsf{margin:5px; padding:0; overf css中text-indent 怎么用rt p { text-indent:2em; } 代码 dl dt dd宽度的问题#help{height:194px;padding:5px 0;clear:both;}#help dl{width:150px;float:left;padding:5px 10px;}#help dt{height:25px;width:150px;text-indent:-2000px;}#help dt.cpzhongxin{background:url(/images/bg_top_foot.png) -365px -170px no-r p {text-indent:5em;}前面的p什么意思 text-indent设置的值很大,作用是什么? text 英语翻译英文翻译The main text is in 10pt Times New Roman.It is double justified with single line spacing.Do not indent the first lines of the first paragraphs within sections. #nav li a{ color:#000; text-decoration:none; padding-top:4px; display:block; width:97px; height:22px ;text-align:center; background-color:#ececec; margin-left:2px; list-style-type:none; } a:link,a:visited {font-size:12px;text-decoration:none;} 为什么我弄a:hover{text-decoration:underline;}下划线不出来呢?.experts_cont li{width:300px; height:360px; float:left;list-style:none;text-decoration:none; margin-right:25px; margin-top:20px;}.experts_cont li a:hover{text-decoration:underlin html a标签中的文字怎么居中对齐<style type="text/css">.btn:hover{font-size:22px;}.btn{color:#000;background:#eaeaea}.a{text-decoration:none;font-size:20px;font-weight:bold;width:222px;height:100px;border:1px solid red}</