.main-menu__list li.active > a {
    color: #7FA26A; /* your brand green */
    font-weight: 600;
}

/* Optional: underline indicator */
.main-menu__list li.active > a::after {
    content: '';
    display: block;
    height: 2px;
    background-color: #7FA26A;
    margin-top: 2px;
    border-radius: 2px;
}