Search Widget Is Huge

Hello All! I am designing my first website using WP and the theme Tempera. I want to add a search box to my page header so I added it using the Widgets page.

Unfortunately the search box is WAY too big. It too tall, wide, and the font is huge.

Here is a screenshot:

http://i144.photobucket.com/albums/r177/tackyjan/Public%20Junk/WordPress/ytp_wp_search-widget-huge_zps6135a062.png

Is there a way I can change the size of the search box? Or use another one?

Thank you.