tr not displaying border-bottom - html

Question

I'm trying to create a datagrid and stumbled on two problems.
I had to use border-collapse: separate; to get round corners on top.
But by doing that I lost the ability to add borders on tr botton.
Any insights?
http://fiddle.jshell.net/KNb7K/
css:
table.dgrid {
border: solid 1px #CDCDCD;
.border-radius(8px, 0px, 0px, 8px);
width: 100%;
border-collapse: separate;
}
table.dgrid th:first-child{
.border-radius(0px, 0px, 0px, 8px);
}
table.dgrid th:last-child{
.border-radius(8px, 0px, 0px, 0px);
}
table.dgrid th{
background-color: #E6E6E6;
}
table.dgrid tr th:last-child, table.dgrid tr td:last-child{
border-right: 0px;
}
table.dgrid tbody tr:last-child {
border-bottom: 0;
}
table.dgrid tr {
border-bottom: solid 1px #CDCDCD;
border-collapse: collapse ;
}
table.dgrid th, table.dgrid td {
padding: 5px;
text-align: center;
vertical-align: middle;
border-right: solid 1px #CDCDCD;
}
html:
<table class="dgrid">
<thead>
<tr>
<th>Ativar</th>
<th>Imagem</th>
<th>Posição</th>
<th>Link</th>
<th>Excluir</th>
</tr>
</thead>
<tbody>
<tr>
<td><input type="checkbox" /></td>
<td></td>
<td></td>
<td><input type="text" /></td>
<td></td>
</tr>
<tr>
<td><input type="checkbox" /></td>
<td></td>
<td></td>
<td><input type="text" /></td>
<td></td>
</tr>
<tr>
<td><input type="checkbox" /></td>
<td></td>
<td></td>
<td><input type="text" /></td>
<td></td>
</tr>
</tbody>
</table>

Answer 1

You can put the bottom-border on table.dgrid th, table.dgrid td and then I would update the table.dgrid tbody tr:last-child to have the td in there like so: table.dgrid tbody tr:last-child td.

Answer 2

Remove border-collapse: separate; from table.dgrid.

Answer 3

this works:
table.dgrid {
width: 98%;
border-collapse: separate;
border-bottom: solid 1px #CDCDCD;
margin:1%;
}
table.dgrid th:first-child{
border-top-left-radius: 8px;
}
table.dgrid th:first-child, table.dgrid td:first-child{
border-left: solid 1px #CDCDCD;
}
table.dgrid th:last-child{
border-top-right-radius: 8px;
}
table.dgrid th{
background-color: #E6E6E6;
}
table.dgrid tbody tr:last-child {
border-bottom: 0;
}
table.dgrid th, table.dgrid td {
padding: 5px;
text-align: center;
vertical-align: middle;
border-top: solid 1px #CDCDCD;
border-right: solid 1px #CDCDCD;
}