css file is not loading on the page

Question

www.septembris.lv Css file is not loading, I can't find out why.

There is a code in html:

<base href="http://www.septembris.lv/">
<link rel="stylesheet" href="assets/css/style.css" />

File itself opening from the browser: http://www.septembris.lv/assets/css/style.css

Answer 1

assets/css/style.css is loaded without any problem

I think the problem is bootstrap.min.css not be loaded, so the website looks like broken.