header{
height: 68px;
width: 100%;
background-color: yellow;
}

.logo{
    text-align: center;   
}
.logo img{
    margin-top: 5px;
}

.nav ul {
    margin-top: 0px;  
    margin-bottom: 0px;
    text-align: center;
}
.nav ul li{
    display: inline-block;
    margin: 0 15px 0 15px;
}