.fraction {
    display: inline-block;
    vertical-align: middle; 
    margin: 0 0.2em 0.4ex;
    text-align: center;
}
.fraction > span {
    display: block;
    padding-top: 0.15em;
}
.fraction span.fup {text-align : center;}
.fraction span.fdn {text-align : center; margin-top : 0.4em; border-top: thin solid black;}
.fraction span.bar {display: none;}