body {
	background:#ddd;
	color:#222;
	max-width:72ch;
	text-align:justify;
	margin:auto;
	padding:1em 0;
	font-family:sans-serif;
	line-height:1.3;
}
a {text-decoration:none;color:#00f;}
h1,h2,h3 {text-align:center}
h1 {font-size:200%;}
h2 {font-size:160%;}
h3 {font-size:120%;}
.nav {height:3rem;font-size:250%;}
.nav a:link,a:visited {color:#222;}
.nav a:hover,a:focus,a:active {color:#00f;}
.navl {width:30%;float:left;text-align:left;}
.navr {width:70%;float:left;text-align:right;}
pre {filter:invert(100%);}
@media (prefers-color-scheme: dark) {
	body {background:#222;filter:invert(100%);}
}