Onetone theme navigation

Hi,
I just created my very first website (onetone – free version) and am having a few issues that I struggle to fix. I hope someone can give me a hand? I am not an expert at all so would really appreciate detailed answers ??

1. Navigation (hover colour) : I would like to change the colour the hover colour in the site navigation. It is currently brown. I tried to add the following to the code but with no result:
.home-navigation li a:hover {
color: #fff;
}

2. Navigation: When clicking on the different sections in the menu I get directed to the right sections on the page. However the hover over colour in the navigation is on the wrong menu point.

3. When viewed on a mobile phone the navigation looks a bit messy (menu items not aligned) and I am not sure why.

Many thanks in advance!