css reset指的是什么

# tmall 天猫商城

body,h2,h3,h4,h5,h6,h7,hr,p,blockquote,dl,dt,dd,ul,ol,li,pre,
form,fieldset,legend,button,input,textarea,th,td  {margin:0;padding:0;}

body,button,input,select,textarea{font:12px/1.5     tahoma,arial,\5b8b\4f53;}

h2,h3,h4,h5,h6,h7{font-size:100%;}

address,cite,dfn,em,var{font-style:normal;}

code,kbd,pre,samp{font-family:courier new,courier,monospace;}

small{font-size:12px;}

ul,ol{list-style:none;}

a{text-decoration:none;}

a:hover{text-decoration:underline;}

sup{vertical-align:text-top;}

sub{vertical-align:text-bottom;}

legend{color:#000;}

fieldset,img{border:0;}

button,input,select,textarea{font-size:100%;}

table{border-collapse:collapse;border-spacing:0;}

# tudou 土豆网

h2,h3,h4,h5,h6,h7,pre,form,
fieldset,input,textarea,p,blockquote,th,td{margin:0;padding:0}

body{color:#000;background:#fff;font-size:12px;line-    height:1.25;font-family:tahoma,arial,\5b8b\4f53,sans-serif}

th,td{text-align:left;vertical-align:top}

h2,h3,h4,h5,h6,h7{font-size:1em;font-weight:normal}

p{margin:0 0 1em 0}

blockquote{margin:0 0 1em 0}

a{color:#14647d;text-decoration:none;font-family:tahoma,arial,\5b8b\4f53,sans-serif;_font-family:arial,sans-serif}

a:hover{text-decoration:underline}

img{display:block;border:0}

li{list-style:none}

ol{padding:0 0 0 2em}

input,label,select,option,textarea,button,fieldset,legend{font-size:1em;font-family:tahoma,arial,\5b8b\4f53,sans-serif;_font-family:Arial,sans-serif}

input[type=text],textarea{-webkit-appearance:none;-webkit-border-radius:0;outline:none}

input.text{color:#444;border-color:#9f9f9f #dcdcdc #dcdcdc #9f9f9f;border-style:solid;border-width:1px;padding:3px 2px;height:14px}

input.radio,input.checkbox{margin-right:2px;vertical-align:-2px}

input.radio,input.checkbox{margin-left:-2px}

label.radio,label.checkbox{margin-right:5px}

textarea{border-color:#9f9f9f #dcdcdc #dcdcdc #9f9f9f;border-style:solid;border-width:1px;padding:1px;resize:none}

# suhu 搜狐

/* 全局CSS定义 */
body{font-family:’宋体';text-align:center;margin:0 auto;padding:0;background:#FFF;font-size:12px;color:#333;}

body > div{text-align:center;margin-right:auto;margin-left:auto;}

div,form,ul,ol,li,span,p{margin:0;padding:0;border:0;}

img,a img{border:0;margin:0;padding:0;}

h2,h3,h4,h5,h6,h7{margin:0;padding:0;font-size:12px;font-weight:normal;}

ul,ol,li{list-style:none}

table,td,input{font-size:12px;padding:0}

/* 默认链接颜色 */
a{outline-style:none;color:#333;text-decoration:none}
a:hover{color:#c00;text-decoration:underline;}