I don't understand. This is a very simple document and I can't see any reason it shouldn't work.
CSS:
.button {
background-color: transparent;
border-radius: 50%;
border: 5px solid #ff0099;
display: table-cell;
vertical-align: middle;
height: 175px;
width: 175px;
text-decoration:none;
text-align: center;
word-wrap: break-word;
}
.button:hover {
text-decoration: underline;
}
.button p {
font-family: Helvetica, Arial, sans-serif;
font-weight: 100;
}
table {
border-spacing: 20px 10px;
border-collapse: separate;
}
td {
vertical-align:middle;
}
HTML:
<table>
<tr>
<td>
<a href="#" class="button" target="_blank"><p>Insert text here, enough to push it over the edge</p></a>
</td>
<td>
<a href="#" class="button" target="_blank"><p>Insert text here, enough to push it over the edge</p></a>
</td>
</tr>
</table>
As far as I know, vertical-align was meant for use in td's, so I'm not sure why it isn't working.
Add below code to button
css . Refer http://jsbin.com/kixewufe/2/ to view http://jsbin.com/kixewufe/2/edit?html,css,output to view complete code.
vertical-align:middle;
display:inherit;