body {
font-size: 0.625em;
/* Because the browser's default font size is 16 pixels, we have now reduced the body font size to 10 pixels, which is easier for calculations. */
}
p, li { font-size: 1.6em; /* 16px */ }
h1 { font-size: 4.8em; /* 48px */ }
h2 { font-size: 2.8em; /* 36px */ }
h3 { font-size: 2.0em; /* 24px */ }
h4 { font-size: 2.0em; /* 21px */ } 
h5 { font-size: 1.8em; /* 18px */ }
h6 { font-size: 1.6em; /* 16px */ }