.com-nav-menu {
    display: flex;
    padding: 0 10px;
    background: #000;
}

.com-nav-menu a {
    position: relative;
    width: 33.3%;
    font: 400 14px/36px '微软雅黑';
    color: #fff;
    text-align: center;
}

.com-nav-menu a.active::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -11px;
    width: 100%;
    height: 12px;
    background: url(../images/leval_san.png) no-repeat center 0/8px;
}

@media (min-width: 1200px) {
    .com-nav-menu {
        padding: 0 20px;
    }

    .com-nav-menu a {
        width: 120px;
        font: 400 14px/42px '微软雅黑';
    }

    .com-nav-menu a.active::after {
        bottom: -11px;
        height: 12px;
        background: url(../images/leval_san.png) no-repeat center 0;
    }
}