.top_menu {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border-bottom: 1px solid #eeeeee;
    border-top: 1px solid #eeeeee;  
    text-align: center;
}

.top_menu li {
    display: inline-block;
}

.top_menu li a {
    display: block;
    color: #2C3E50;
    text-align: center;
    padding: 18px 20px;
    text-decoration: none;
    font-family: sans-serif;
    letter-spacing: 0.75px;
    text-transform: uppercase;
    font-size: 13px;
}
.top_menu li a:hover:not(.active) {
    font-weight: bold;
}

.active {
    font-weight: bold;
}

@media only screen and (min-width: 1500px) {

    .top_menu li a {
        padding: 22px 24px;
        font-size: 18px;
    }
}

@media only screen and (max-width: 620px) {

    .top_menu li a {
        padding: 10px 8px;
        font-size: 8px;
    }
}