The default theme of drupal make some problems

The default theme of drupal make some strange problems. If I create a form that contains a markup:

$form['markup'] = array(
'#type' => 'markup',
'#value' => '<table><tr><td> test </td></tr></table>');

The browser displays the table, however the property 'border-collapse' of the css style of the table is setted to 'collapse'. It means that I see a small grey line above my table and It's not very beautifull to see that.

One of the solution is to fix by myself the value of border-collapse into the property of the table but before doing this I wanna be sure that there isn't any other solution to avoid this.

My problem is : is it normal that the default theme of drupal force some strange behavior with some HTML element (e.g. table).

Do you have a kin开发者_如何学运维d of answer?

It's normal for the default theme to set something like "border-collapse", yes. The small grey line sounds unintended, perhaps from an assumption about tables that isn't true in your table, e.g. a distinct <thead> and <tbody>. Your use of the word "force" sounds like you may be happier with a base theme you can more easily customize.