*         { box-sizing: border-box;
            margin: 0px;
            color: lightgrey; }
p.big     { font-size:2.25em; }
a         { text-decoration:none; }
a:hover   { color:black; }
body      { background:#272727;
            height: 100vh;
            display: flex;
            flex-flow: column nowrap;
            padding: 5px;
            font-size:1em }
.main     { flex-grow: 1;
            display: flex;
            justify-content: center;
            align-items: center; }
.footer   { flex-grow: 0; }
.box      { font-size:0.8em;
            text-align: center; }

/* borders 
body      { border: 4px solid yellow;}
.main     { border: 2px solid darkorange;}
.footer   { border: 2px solid darkgreen;}
.box      { border: 2px solid darkblue;}
*/