Why does my <ul> show up like this? (Wordpress) - html

Question

I'm trying to make my website with Wordpress.
I wanted to add my custom horizontal menu, with plain CSS and HTML since plugins can't satisfy me.
This is my HTML code:
<div id="provamenutop">
<ul>
<li>Home</li>
<li>Home</li>
<li>Home</li>
<li>Home</li>
<li>Home</li>
</ul>
</div>
and this is my CSS:
#provamenutop {background-color:#333; width:90%; line-height:100%;}
#provamenutop li {position: relative; float:left; list-style: none; font-family:verdana;}
#provamenutop li a {display:inline-block; text-decoration:none; padding: 20px; color: white; background: #333; transition:.4s;}
#provamenutop li a:hover {background: #111;}
On my local computer, this looks right:
https://gyazo.com/d5b38f6cc1c7857dbe37945e2d8b5002
But here's what it looks like on my website, using a custom theme called Sportexx:
https://gyazo.com/5ccb7e944b627244a7d3ac8344471b28
I know this could be some CSS already existing in the theme interfering with mine, but what could I do to avoid the problem? (The space in between one Home button and the other is also clickable)
Thank you for reading.

Answer 1

When you use Chrome Developer Tools or Firefox Firebug and inspect the HTML, you will see the following output for your menu on the web site http://www.ferrari.co.it/athletic/
<div id="provamenutop">
<ul>
<li>Home</li><a href="#">
</a><li>Home</li><a href="#">
</a><li>Home</li><a href="#">
</a><li>Home</li><a href="#">
</a><li>Home</li><a href="#">
</a></ul><a href="#">
</a>
</div>
So the problem here is not CSS, but faulty HTML. You have two additional <a href...></a> tags. One before the Home and one outside the closing </li> tag and also one outside the closing </ul> tag.
If you fix your HTML, so that it looks like this, it will actually work:
<div id="provamenutop">
<ul>
<li>Home</li>
<li>Home</li>
<li>Home</li>
<li>Home</li>
<li>Home</li>
</ul>
</div>

Answer 2

It's definitely a CSS conflicting issue. Do you have a link so we can check it in firebug? Should be a very easy fix. When I run your html and css in JSFiddle it works fine.
I'm not sure what you mean by On my local computer, this looks right:
But here's what it looks like on my website, using a custom theme
called Sportexx:
Are you not using sportexx on your local computer? If it's working without the theme and not working with the theme it's the CSS. Just open up firebug in your browser and look at the css around the menu. You should be able to adjust it right there and remove the problem. Then go to your stylesheet and make the changes accordingly.
After seeing your comment. It's the html. Just delete the other links.