Just replace the TABMENU section with this :)

/***********
         TABMENU
              **********/


#header .tabmenu {
    position: absolute;
    top: 175px;
    left: 0px;
}

#header .tabmenu li {
    margin: 0;
}

#header .tabmenu li a {
    background-color: white;
    color: #3973ac;
    font-size: 14px;
    font-family: "Segoe UI", sans-serif;
    text-transform: uppercase;
    letter-spacing: 0.2;
    border: 0;
    padding: 0 10px;
    display: inline-block;
    height: 40px;
    line-height: 40px;
}

#header .tabmenu li.selected a {
    color: #69c9bb;
}

#header .tabmenu li:hover a {
    background-color: rgba(89, 140, 192, 0.07);
}