Blank space after header.php

I’m a complete novice at WordPress. The question I’m asking might sound trite, but I truly don’t know to solve this issue. The problem is that when I try to rescale the website homepage there’s some blank space left after header.php – https://puu.sh/cqaZk/4aab65a78b.jpg. The issue doesn’t persist on other pages – https://puu.sh/cqbdl/72729f4804.png.

Website: https://vegankitchen.ru/

Nav code:

<!– begin nav –>
<div class=”nav-wrapper”>
<nav>
</nav>
</div>
<div class=”clear”></div>
<!– end nav –>

Looking forward to the reply!