1. Well you could set the margin to zero for the li
Code:
#ul#navi-menu li a.home, #ul#navi-menu li a.adopt, #ul#navi-menu li a.mypets, #ul#navi-menu li a.mail, #ul#navi-menu li a.blank, #ul#navi-menu li a.settings{
margin-left: 0px;
margin-right: 0px;
}
2. On my browser [ im using chrome ] it is already centered. maybe you can use a negitive margin for the top of the id main
Code:
#main{
margin-top: -10px;
}
3. I would suggest you remove the blue borders. they dont fit in well with the layout.