body { max-width:650px; margin: 50px auto; padding: 0 15px; font: 16px/1.6 Arial, sans-serif;
    color:#444;}
h1,h2,h3 { line-height: 1.5}
@media (prefers-color-scheme: dark) {
    body {color:white ; background:#444} a:link{color:#5bf}a:visited{color:#ccf}
}