nav.nav-center ul{
  text-align: center;
}
.li a:hover {    
  background-color:#eee;
  color:black;
} 
.li a.active {
  color:#000;
} 
.li a{
  color:#fff;
  border-right: solid 1px grey;
}
nav.nav-center ul li{
  display: inline;
  float: none;
}  
nav.nav-center ul li a{
  display: inline-block;
}
#fot{  
      background: linear-gradient(45deg, #212121 24%, rgba(255,255,255,1) 24%);
    }
    footer {
      padding: 30px;
    }
    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }