/**
 * Navigation Component
 * Header navigation styles with responsive mobile menu
 */

.nav-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-fixed);
    background-color: var(--color-white);
    box-shadow: var(--shadow-sm);
    transition: background-color var(--transition-base),
                box-shadow var(--transition-base);
}

.nav-header.scrolled {
    background-color: var(--color-white);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--space-4) var(--container-padding);
    height: 80px;
}

/* Logo */
.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    z-index: 10;
}

.logo-image {
    height: 32px;
    width: auto;
    object-fit: contain;
}

.logo-text {
    font-size: var(--text-xl);
    font-weight: var(--font-bold);
    color: var(--text-primary);
    letter-spacing: var(--tracking-tight);
    transition: color var(--transition-base);
}

/* Navigation Menu */
.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.nav-link {
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--text-primary);
    letter-spacing: var(--tracking-wide);
    transition: color var(--transition-fast), opacity var(--transition-fast);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: currentColor;
    transition: width var(--transition-base);
}

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

.nav-link:hover {
    opacity: 0.8;
}

/* Navigation CTA Button */
.nav-cta {
    padding: var(--space-3) var(--space-6);
    font-size: var(--text-sm);
}

/* Mobile-only elements hidden on desktop */
.nav-mobile-cta {
    display: none;
}

.nav-mobile-models {
    display: none;
}

/* Mobile Menu Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    z-index: 10;
}

.hamburger {
    width: 24px;
    height: 2px;
    background-color: var(--text-primary);
    position: relative;
    transition: background-color var(--transition-fast);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 24px;
    height: 2px;
    background-color: var(--text-primary);
    transition: transform var(--transition-base);
}

.hamburger::before {
    top: -8px;
}

.hamburger::after {
    top: 8px;
}

.nav-header.scrolled .hamburger,
.nav-header.scrolled .hamburger::before,
.nav-header.scrolled .hamburger::after {
    background-color: var(--text-primary);
}

/* Mobile menu open state */
.nav-toggle.active .hamburger {
    background-color: transparent;
}

.nav-toggle.active .hamburger::before {
    transform: rotate(45deg) translate(5px, 6px);
}

.nav-toggle.active .hamburger::after {
    transform: rotate(-45deg) translate(5px, -6px);
}

/* ===========================================
   Models Dropdown
   =========================================== */

.nav-dropdown {
    position: relative;
}

.nav-dropdown-panel {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(8px);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-fast), transform var(--transition-fast), visibility var(--transition-fast);
    padding-top: var(--space-4);
    z-index: var(--z-dropdown);
}

.nav-dropdown:hover .nav-dropdown-panel {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.nav-dropdown-grid {
    display: flex;
    gap: var(--space-4);
    background: var(--color-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    padding: var(--space-4);
    border: 1px solid var(--border-light);
}

.nav-dropdown-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-5);
    border-radius: var(--radius-md);
    transition: background-color var(--transition-fast);
    text-align: center;
    width: 180px;
}

a.nav-dropdown-item:hover {
    background-color: var(--color-gray-50);
}

.nav-dropdown-item img {
    width: 140px;
    height: 90px;
    object-fit: contain;
}

.nav-dropdown-name {
    font-size: var(--text-lg);
    font-weight: var(--font-semibold);
    color: var(--text-primary);
}

.nav-dropdown-item .btn {
    padding: var(--space-2) var(--space-5);
    font-size: var(--text-xs);
    width: 100%;
    border-color: var(--text-primary);
    pointer-events: none;
}

/* ===========================================
   Responsive Styles
   =========================================== */

@media (max-width: 1024px) {
    .nav-menu {
        gap: var(--space-6);
    }
}

@media (max-width: 768px) {
    .logo-image {
        height: 24px;
    }

    .logo-text {
        font-size: var(--text-base);
    }

    .nav-toggle {
        display: flex;
    }

    /* ---- Mobile Menu Overlay ---- */
    .nav-menu {
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        z-index: var(--z-modal);
        flex-direction: column;
        justify-content: flex-start;
        align-items: stretch;
        gap: 0;
        padding: 80px var(--container-padding) var(--container-padding);
        background-color: var(--color-white);
        transform: translateX(100%);
        transition: transform var(--transition-base);
        overflow-y: auto;
    }

    .nav-menu.active {
        transform: translateX(0);
    }

    /* ---- Mobile Menu Links ---- */
    .nav-menu > li {
        border-bottom: 1px solid var(--border-light);
    }

    .nav-menu .nav-link {
        display: flex;
        align-items: center;
        justify-content: space-between;
        width: 100%;
        padding: var(--space-5) 0;
        font-size: var(--text-base);
        font-weight: var(--font-medium);
        color: var(--text-primary);
    }

    .nav-menu .nav-link::after {
        display: none;
    }

    /* Arrow for dropdown trigger on mobile */
    .nav-menu .nav-dropdown .nav-link::after {
        display: block;
        content: '';
        position: static;
        width: 8px;
        height: 8px;
        border-right: 2px solid var(--text-secondary);
        border-bottom: 2px solid var(--text-secondary);
        transform: rotate(-45deg);
        background: none;
        flex-shrink: 0;
    }

    /* ---- Desktop CTA hidden, mobile CTA at bottom ---- */
    .nav-cta {
        display: none !important;
    }

    .nav-mobile-cta {
        display: block;
        margin-top: auto;
        padding-top: var(--space-6);
    }

    .nav-mobile-cta .btn {
        width: 100%;
        justify-content: center;
    }

    /* ---- Raise header z-index when menu is open ---- */
    .nav-header.menu-open {
        z-index: var(--z-modal);
        backdrop-filter: none;
    }

    /* ---- Hamburger colours when open ---- */
    .nav-header.menu-open .nav-toggle {
        z-index: calc(var(--z-modal) + 1);
    }

    .nav-header.menu-open .hamburger {
        background-color: transparent;
    }

    .nav-header.menu-open .hamburger::before,
    .nav-header.menu-open .hamburger::after {
        background-color: var(--text-primary);
    }

    .nav-header.menu-open .nav-logo {
        visibility: hidden;
    }

    /* ---- Desktop dropdown hidden on mobile ---- */
    .nav-dropdown-panel {
        display: none;
    }

    /* ---- Mobile Models Sub-Panel ---- */
    .nav-mobile-models {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        z-index: var(--z-modal);
        background-color: var(--color-white);
        padding: 0 var(--container-padding) var(--container-padding);
        overflow-y: auto;
        flex-direction: column;
    }

    .nav-mobile-models.active {
        display: flex;
    }

    .nav-mobile-models-header {
        display: flex;
        align-items: center;
        justify-content: space-between;
        height: 80px;
        flex-shrink: 0;
    }

    .nav-mobile-back {
        display: flex;
        align-items: center;
        gap: var(--space-2);
        font-size: var(--text-sm);
        font-weight: var(--font-medium);
        color: var(--text-primary);
        background: none;
        border: none;
        padding: 0;
        cursor: pointer;
    }

    .nav-mobile-back svg {
        width: 20px;
        height: 20px;
    }

    .nav-mobile-models-title {
        font-size: var(--text-base);
        font-weight: var(--font-semibold);
        color: var(--text-primary);
        position: absolute;
        left: 50%;
        transform: translateX(-50%);
    }

    .nav-mobile-close {
        display: none;
    }

    /* ---- Mobile Model List Items ---- */
    .nav-mobile-model-list {
        display: flex;
        flex-direction: column;
    }

    .nav-mobile-model-item {
        display: flex;
        align-items: center;
        gap: var(--space-4);
        padding: var(--space-5) 0;
        border-bottom: 1px solid var(--border-light);
    }

    .nav-mobile-model-item img {
        width: 100px;
        height: 64px;
        object-fit: contain;
        flex-shrink: 0;
    }

    .nav-mobile-model-info {
        display: flex;
        flex-direction: column;
        gap: var(--space-1);
    }

    .nav-mobile-model-name {
        font-size: var(--text-lg);
        font-weight: var(--font-semibold);
        color: var(--text-primary);
    }

    .nav-mobile-model-links {
        display: flex;
        gap: var(--space-4);
    }

    .nav-mobile-model-links a {
        font-size: var(--text-sm);
        font-weight: var(--font-medium);
        color: var(--text-secondary);
        transition: color var(--transition-fast);
    }

    .nav-mobile-model-links a:hover {
        color: var(--text-primary);
    }

    .nav-mobile-model-links span {
        font-size: var(--text-sm);
        color: var(--text-tertiary);
    }
}