/* Dropdown Navigation Styles */
.nav-dropdown {
    position: relative;
    display: inline-block;
}

.nav-dropdown-toggle {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.3s ease;
    font-weight: 500;
    cursor: pointer;
    padding: 10px 15px;
    display: flex;
    align-items: center;
    gap: 5px;
}

.nav-dropdown-toggle:hover {
    color: var(--primary);
}

.nav-dropdown-toggle::after {
    content: "▼";
    font-size: 0.7rem;
    margin-left: 3px;
    transition: transform 0.3s ease;
}

.nav-dropdown:hover .nav-dropdown-toggle::after {
    transform: rotate(180deg);
}

.nav-dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background: #fff;
    min-width: 280px;
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius-md);
    border: 1px solid #e5e5e5;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.3s ease;
    z-index: 1000;
    margin-top: 10px;
}

.nav-dropdown:hover .nav-dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.nav-dropdown-item {
    padding: 15px 20px;
    border-bottom: 1px solid #f0f0f0;
    transition: background-color 0.2s ease;
}

.nav-dropdown-item:last-child {
    border-bottom: none;
}

.nav-dropdown-item:hover {
    background-color: var(--bg-light);
}

.nav-dropdown-item a {
    text-decoration: none;
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.nav-dropdown-icon {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 600;
    font-size: 0.9rem;
}

.nav-dropdown-content h4 {
    color: var(--text-main);
    font-size: 0.95rem;
    margin: 0 0 4px 0;
    font-weight: 600;
}

.nav-dropdown-content p {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin: 0;
    line-height: 1.4;
}

.nav-dropdown-item:hover .nav-dropdown-content h4 {
    color: var(--primary);
}

/* --- Sub-Dropdown (Robotics fly-out) --- */
.nav-sub-dropdown {
    position: relative;
}

.nav-sub-dropdown>a {
    position: relative;
}

.nav-sub-arrow {
    margin-left: auto;
    font-size: 1.2rem;
    color: var(--text-muted);
    transition: transform 0.3s ease, color 0.3s ease;
    flex-shrink: 0;
}

.nav-sub-dropdown:hover .nav-sub-arrow {
    color: var(--primary);
    transform: translateX(3px);
}

.nav-sub-menu {
    position: absolute;
    left: 100%;
    top: 0;
    background: #fff;
    min-width: 250px;
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius-md);
    border: 1px solid #e5e5e5;
    opacity: 0;
    visibility: hidden;
    transform: translateX(-10px);
    transition: all 0.3s ease;
    z-index: 1001;
    margin-left: 4px;
}

.nav-sub-dropdown:hover>.nav-sub-menu {
    opacity: 1;
    visibility: visible;
    transform: translateX(0);
}

.nav-sub-menu .nav-dropdown-item {
    padding: 12px 16px;
}

.nav-sub-menu .nav-dropdown-item:first-child {
    border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.nav-sub-menu .nav-dropdown-item:last-child {
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    border-bottom: none;
}

.nav-sub-menu .nav-dropdown-icon {
    width: 32px;
    height: 32px;
    font-size: 0.6rem;
}

.nav-sub-menu .nav-dropdown-content p {
    font-size: 0.78rem;
    color: var(--text-muted);
    margin: 0;
}

/* Highlight active robotics item when sub-menu is open */
.nav-sub-dropdown:hover {
    background-color: var(--bg-light);
}

/* Mobile responsive */
@media (max-width: 768px) {
    .nav-dropdown-menu {
        position: static;
        min-width: 100%;
        transform: none;
        margin-top: 10px;
        display: none;
        /* Fix: Hide by default so it doesn't take space */
    }

    .nav-dropdown:hover .nav-dropdown-menu {
        display: none;
    }

    .nav-dropdown.active .nav-dropdown-menu {
        display: block;
        opacity: 1;
        visibility: visible;
    }

    .nav-sub-menu {
        position: static;
        min-width: 100%;
        box-shadow: none;
        border: none;
        border-left: 3px solid var(--primary);
        margin-left: 15px;
        margin-top: 0;
        padding-left: 0;
        border-radius: 0;
        opacity: 0;
        visibility: hidden;
        display: none;
        transform: none;
    }

    .nav-sub-dropdown:hover>.nav-sub-menu,
    .nav-sub-dropdown.active>.nav-sub-menu {
        display: block;
        opacity: 1;
        visibility: visible;
        transform: none;
    }

    .nav-sub-arrow {
        transform: rotate(90deg);
    }

    .nav-sub-dropdown:hover .nav-sub-arrow,
    .nav-sub-dropdown.active .nav-sub-arrow {
        transform: rotate(90deg) translateX(3px);
    }
}