[Theme: Asteroid] Nav bar size

Hello. I’m very bad with coding. I just have a simple problem.

I have a navigation bar. It looks something like this:

.Space. Button Text .Space. Button Text .Space.

All the buttons are centered. They all go the left side (as opposed to being equally stretched along the entire nav bar). All I want is to reduce the space between each button.

I have opened style.css of my theme. Please tell me what I must add to reduce the horizontal spacing. Link – http://www.oldpcgaming.net/

<backsticks>
#nav {
background-color: #333;
border-top: 1px solid #000;
border-bottom: 1px solid #000;
float: left;
width: 100%;
z-index: 20;
}
#nav .menu {float: left; border-right: 1px solid #555;}

#nav .menu li {float: left; position: relative;}

#nav .menu li a {
display: block;
padding: 6px 1px;
font: 13px arial, sans-serif;
color: #FFF;
text-shadow: 0 2px 2px #000;
}</backsticks>