body {background-color: black; }

div.start {text-align: center; color:white; font-size: 20pt; font-family: Arial, Helvetica, sans-serif;}
div.go {width: 500px; display: block; margin-left: auto; margin-right: auto; text-align: justify;
color:white; font-size: 12pt; font-family: courier, monospace;}

iframe {
    display: block;
    margin-left: auto;
    margin-right: auto;
       }

img.header {max-width: 100%; height: auto}