mystyle.css

.article {
	width: 100%;
	max-width: 50em;
	margin: 0 auto;
	font-family: Arial; 
	padding: 1em;
	counter-reset: figures;
}

.figure {
	padding: 0.9em;
	margin: 0 auto 1em;
}

.figure figcaption {
	text-align:center;
	counter-increment: figures;
}

.figure figcaption:before {
	font-weight: bold;	
	content: 'Figure ' counter(figures) ' . ';
}

.body {
	margin: 0 auto;
	font-family: Arial;
    counter-reset: section;
}

.h3 {
    counter-reset: subsection;
}

.h3:before {
    counter-increment: section;
    content: "Section " counter(section) ". ";
}

.h3:before {
    counter-increment: subsection;
    content: counter(section) "." counter(subsection) " ";
}