We frequently see our members posting in our forum that after installing the package (step 1), the site doesn't look like your JoomBri Careers Demo site.
JoomBri Careers is just a component and it doesn't include any template. The template we have used in our demo site is JB Blossom based on yootheme.com Warp Framework.
After installing the template, set it as the default template in Extensions → Templates.