Changes
border: 1px gray solid;
background: #e9e9e9;
}
table.ibox > caption {
font-weight: bold;
}
table.ibox > tr > th,
table.ibox > tr > td,
table.ibox > * > tr > th,
table.ibox > * > tr > td {
border: 1px #aaa solid;
padding: 0.2em;
}
table.ibox > tr > th,
table.ibox > * > tr > th {
background-color: #f2f2f2;
text-align: center;
}