.invoice .optional {
    display: none;
}
.invoice-table {
  border: 1px solid #ccc;
  border-collapse: collapse;
  margin:0;
  padding:0;
  width: 100%;
}
.invoice-table tr {
  border: 1px solid #ddd;
  padding: 5px;
}
.invoice-table th, .invoice-table td {
  padding: 10px;
  text-align: center;
}
.invoice-table th {
  font-size: 14px;
  letter-spacing: 1px;
  text-transform: uppercase;
}
@media screen and (max-width: 600px) {
  .invoice-table {
    border: 0;
  }
  .invoice-table thead {
    display: none;
  }
  .invoice-table tr {
    border-bottom: 2px solid #ddd;
    display: block;
    margin-bottom: 10px;
  }
  .invoice-table td {
    border-bottom: 1px dotted #ccc;
    display: block;
    font-size: 13px;
    text-align: left;
  }
  .invoice-table td:last-child {
    border-bottom: 0;
  }
  .invoice-table td:before {
    content: attr(data-label);
    float: left;
    font-weight: bold;
    text-transform: uppercase;
  }
}