A Simple Way to Dynamically Change Style of Web for Each Browser

body 
{
	background-color:Fuchsia;
	font-family:'Times New Roman';
	font-size:medium;
	font-weight:normal;
	margin:0px;
}
#mainContent
{
	padding-top:10px;
	padding-left:20px;
	padding-bottom:10px;
	background-color:Orange;
}
#header
{
	float:none;
	background-color:Silver;
	font-style:normal;
	font-size:large;
	margin:20px;
	padding:10px;
}
#info
{
	background-color:#fc4322;
	font-size:small;
	float:left;
	color:Black;
	width:500px;
	height:100px;
	padding:10px;
	margin:10px;
}