Control Fieldset Width in a Block?

Question

Anyone know how to control the width of a drupal fieldset that's in a block? I have a custom block that I've added 3 fieldsets to using the same exact fieldset code in each, however out of the three, the top one's width is fine, the middle one's is overflowing into the middle column, and then last one is fine. The screenshot shows the top block and the "broken one below it. I want the width to be the same as the top block, which is automatically setting it's width the same as all of the rest of the other blocks in the same column.

Screenshot

Answer 1

I would do this with CSS as @Ivanhoe123 suggested.

fieldset {
    width: 100px;
}