div.casestudy {
width: 600px;
margin: 1em auto;
text-align: left;
}
div.casestudy p { margin-bottom: 1em; }
div.casestudy b { color: orange;
    display: block;
    margin-bottom:0.25em;
}

div#navigation { margin: 2em; text-align: center;}
div#navigation img {width: 48px; height: 48px; 
    background-color: lightgreen;
    padding: 12px; margin: 4px;
    border-radius: 6px; 
}
div#navigation a { text-decoration: none; }