.nav ul li#sy a{color:#C60001;}
.nav ul li#sy::after {
    content: '';
    display: block;
    width: 0;
    height: 0;
    border-bottom: 7px solid #C60001;
    border-left: 6px solid transparent;
    border-right: 6px solid transparent;
    position: absolute;
    bottom: 0;
    left: 30px;
}