.nav-link {
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #3b82f6;
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

.nav-link.active::after {
    width: 100%;
}