body {
	font-size: 18px;
	font-family: Georgia, serif;
	width: 500px;
	margin: 1.5em auto;
} 

p { 
	font-size: 1em; /* 18px */ 
	line-height: 1.1667em; /* 21px */ 
	margin: 0 0 1.1667em 0;
}

h1 { font-size: 2em; /* 36px */ line-height: 1.1667em; /* 42px */ margin-top: 0.5833em; margin-bottom: 0em; }

h2 { font-size: 1.3333em; /* 24px */ line-height: 1.75em; /* 42px */ margin-top: 0.875em; margin-bottom: 0em; }

you-got18px { font-size: 1em; /* 18px */ line-height: 1.1667em; /* 21px */ margin-top: 1.1667em; margin-bottom: 0em; }
/* 28 - The quick brown fox jumps over the lazy dog */
you-got28px { font-size: 1.5556em; /* 28px */ line-height: 1.5em; /* 42px */ margin-top: 0.75em; margin-bottom: 0em; }
/* 36 - The quick brown fox jumps over the lazy dog */
you-got36px { font-size: 2em; /* 36px */ line-height: 1.1667em; /* 42px */ margin-top: 0.5833em; margin-bottom: 0em; }