Styling table captions with CSS: fixing the width problem

Styling table captions with CSS is not always an easy task. The specific issue I'll be dealing with in this article is the fact that the width of the caption doesn't naturally fit the width of the table. First I'll introduce the problem and then present a cross browser solution.

Our desired table and caption

There's many ways to style tables, I'm going to focus on a table with collapsed borders, and a 1px border around each TH and TD. Also we want a caption that has exactly the same width as the table, which one would think should be quite straight forward to accomplish. Here's how we want our table and caption to look like:

Running intro trouble

Let's add the style to our table, and see what happens:

<table summary="lorem ipsum dolor">
  <caption>Lorem ipsum</caption>

  <tr>
    <th>Lorem ipsum</th>
    <th>Bobis sum</th>
    <th>Populae sonorem</th>
    <th>Ipsum et</th>
  </tr>

  <tr>
    <td>Lorem ipsum</td>
    <td>Bobis sum</td>
    <td>Populae sonorem</td>
    <td>Ipsum et</td>
  </tr>

  <tr>
    <td>Lorem ipsum</td>
    <td>Bobis sum</td>
    <td>Populae sonorem</td>
    <td>Ipsum et</td>
  </tr>

  <tr>
    <td>Lorem ipsum</td>
    <td>Bobis sum</td>
    <td>Populae sonorem</td>
    <td>Ipsum et</td>
  </tr>

</table>

table {
  border-collapse: collapse;
}

caption, th, td {
  padding: .2em .8em;
  border: 1px solid #fff;
}

caption {
  background: #dbb768;
  font-weight: bold;
  font-size: 1.1em;
}

th {
  font-weight: bold;
  background: #f3ce7d;
}

td {
  background: #ffea97;
}

Everything seems simple enough. Note that we add the border to all TH, TD and CAPTION. And it does work in IE6, IE7, Opera... but not Firefox! Firefox's caption is 1px short on the left side, as shown in the following image:

The paradox here is that Firefox is doing the right thing according to the CSS2 specification. That's good news for Firefox fans :) but we still need to find a solution.

The fix

Let's try adding a 1px negative margin to the left of the caption... Sorted! Now the caption has the desired width in Firefox. You would think that this might cause problems in IE, but it doesn't have any effect at all.

Can it be so easy? Well, of course not! And this time Opera treats us with a fancy bug, causing the whole caption to disappear. The space is there, but the caption is gone. My way of fixing this is by canceling the negative margin with an Opera-only statement. Here's the CSS with the fix applied:

table {
  border-collapse: collapse;
}

caption, th, td {
  padding: .2em .8em;
  border: 1px solid #fff;
}

caption {
  background: #dbb768;
  font-weight: bold;
  font-size: 1.1em;
  margin-left: -1px; /* Fix FF 1px issue */
}

html:first-child caption { /* Opera only */
 margin-left: 0;
}

th {
  font-weight: bold;
  background: #f3ce7d;
}

td {
  background: #ffea97;
}