¿Cómo reducir el tamaño de letras en un blog?

/* general reset */
html, body, div, span, object, embed, ruby, output, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre,
abbr, address, cite, code, del, dfn, em, img, ins, kbd, q, samp,
small, strong, sub, sup, var, b, i, dl, dt, dd, ol, ul, li,
fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, figcaption, figure,  footer, header, hgroup, 
menu, nav, section, summary, time, mark, audio, video { 
	margin: 0;
	padding: 0;
	border: 0;
	outline: 0;
	font-size: 100%;
	vertical-align: baseline;
	background: transparent;
}

.site-titlepbt {
font-size: 36px;
}

#containerpbt {
font-size: 12px;
}