Antimatter Dropdown Width

I played with template.css and navigation.twig.html but can't make it. How do I widen the width of dropdown menu. Thanks!

If you inspect the dropdown with Chrome for example, you can see in the developer tools exactly where the width is being set:

Home | Demo2 2014-12-25 11-08-21

If you modify any SCSS, You will need to recompile it to have it take effect.

Alternatively you can put in a more specific css line in your css/custom.css file:

body #header #navbar ul.navigation li:hover > ul { 
  width: 15rem;
}

thank you very much!