How to add spacing between certain columns of a table?

Question

I want to make a table like this:

There should be spacing between C and D, D and E, and F and G. But there shouldn't have any space between any other column, for instance A and B.

This is what I currently have:

JSFiddle: https://jsfiddle.net/e33cbkh3/1/

@import url('https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css');

thead {
background: orange;
}

th, td {
text-align: center;
border: none !important;
}

<table class="table table-striped table-bordered table-hover">
  <thead>
    <tr>
      <th colspan="3"></th>
      <th></th>
      <th colspan="2"> XYZ </th>
      <th></th>
    </tr>
    <tr>
      <th>A</th>
      <th>B</th>
      <th>C</th>
      <th>D</th>
      <th>E</th>
      <th>F</th>
      <th>G</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>1</td>
      <td>2</td>
      <td>3</td>
      <td>4</td>
      <td>5</td>
      <td>6</td>
      <td>7</td>
    </tr>
  </tbody>
</table>

Answer 1

The easiest solution would be to include some additional empty columns in your table:

HTML

<table class="table">
  <thead>
    <tr>
      <th colspan="3"></th>
      <th class="space"></th>
      <th></th>
      <th class="space"></th>
      <th colspan="2"> XYZ </th>
      <th class="space"></th>
      <th></th>
    </tr>
    <tr>
      <th>A</th>
      <th>B</th>
      <th>C</th>
      <th class="space"></th>
      <th>D</th>
      <th class="space"></th>
      <th>E</th>
      <th>F</th>
      <th class="space"></th>
      <th>G</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>1</td>
      <td>2</td>
      <td>3</td>
      <td class="space"></td>
      <td>4</td>
      <td class="space"></td>
      <td>5</td>
      <td>6</td>
      <td class="space"></td>
      <td>7</td>
    </tr>
  </tbody>
</table>

CSS

/* make the cells appear to be empty */
.space {
  background: none;
  /* make the width small, but setting it to 0 will actual default to the same width as other cells */
  width: 0.1rem;
}

You'll also need to move the thead background-color to the th elements:

th {
  background: orange;
}

JSFiddle: https://jsfiddle.net/L43weozq/

Answer 2

By pseudoclasses: https://jsfiddle.net/glebkema/y4ff5m61/

@import url('https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css');

thead {
  background: orange;
}

th, td {
  text-align: center;
  border: none !important;
}

tr:first-child > th:not(:last-child),
tr:last-child > th:nth-child(3), td:nth-child(3),
tr:last-child > th:nth-child(4), td:nth-child(4),
tr:last-child > th:nth-child(6), td:nth-child(6) {
  border-right: 15px solid white !important;
}

<table class="table table-striped table-bordered table-hover">
  <thead>
    <tr>
      <th colspan="3"></th>
      <th></th>
      <th colspan="2">XYZ</th>
      <th></th>
    </tr>
    <tr>
      <th>A</th>
      <th>B</th>
      <th>C</th>
      <th>D</th>
      <th>E</th>
      <th>F</th>
      <th>G</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>1</td>
      <td>2</td>
      <td>3</td>
      <td>4</td>
      <td>5</td>
      <td>6</td>
      <td>7</td>
    </tr>
  </tbody>
</table>