.about-nav {
    border-bottom: 1px solid #dfdfdf;
    max-width: 1200px;
    margin: 0 auto;
    background-color: #fff;
}
.about-nav li {
    float: left;
    width: 15%;
    margin-right: 5%;
    padding: 20px 0 0;
    text-align: center;
}

.about-nav li a {
    font-size: 18px;
}

.about-nav li a:hover {
    color: #3CACC7;
}

.active {
    display: block;
    color: #3CACC7;
    border-bottom: 1px solid #3CACC7;
    height: 40px;
}

@media(max-width:1366px) and (min-width:1200px) {
    .about-nav {
        max-width: 900px;
    }
}