/* ========================================
   HEADER & NAVIGATION
   ======================================== */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-fixed);
    transition: all var(--transition-base);
    padding: var(--space-4) 0;
}

.site-header.scrolled {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
    padding: var(--space-2) 0;
}

.site-header.scrolled .nav-link {
    color: var(--nxt-dark);
}


.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-8);
}

/* Logo */
.site-logo {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    flex-shrink: 0;
    z-index: 10;
}

.site-logo-img {
    height: 42px;
    width: auto;
    display: block;
    object-fit: contain;
}

/* Main Navigation */
.main-nav {
    display: flex;
    align-items: center;
    gap: 0;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 3px;
    padding: var(--space-2) var(--space-2);
    font-size: 0.8125rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.9);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    cursor: pointer;
    white-space: nowrap;
}

.nav-link:hover {
    color: var(--nxt-white);
    background: rgba(255, 255, 255, 0.1);
}

.scrolled .nav-link:hover {
    color: var(--nxt-blue-600);
    background: var(--nxt-blue-50);
}

.nav-link svg {
    width: 16px;
    height: 16px;
    transition: transform var(--transition-fast);
}

.nav-item:hover .nav-link svg {
    transform: rotate(180deg);
}

/* Mega Menu */
.mega-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    min-width: 580px;
    max-width: min(620px, 92vw);
    background: var(--nxt-white);
    overflow-x: hidden;
    overflow-y: auto;
    max-height: 85vh;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-2xl);
    border: 1px solid var(--nxt-light-3);
    padding: var(--space-4) var(--space-5);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: all var(--transition-base);
    z-index: var(--z-dropdown);
}

.nav-item:hover .mega-menu {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateX(-50%) translateY(0);
}

.mega-menu-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2px;
}

.mega-menu-3col {
    grid-template-columns: repeat(3, 1fr);
}

.mega-menu-item {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.mega-menu-item:hover {
    background: var(--nxt-blue-50);
}

.mega-menu-icon {
    width: 32px;
    height: 32px;
    min-width: 32px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 15px;
    background: var(--nxt-light);
    transition: all var(--transition-fast);
}

.mega-menu-item:hover .mega-menu-icon {
    background: var(--nxt-blue-100);
}

.mega-menu-content h4 {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--nxt-dark);
    margin-bottom: 1px;
    line-height: 1.3;
}

.mega-menu-content p {
    font-size: 0.6875rem;
    color: var(--nxt-gray-500);
    margin: 0;
    line-height: 1.3;
}

.mega-menu-header {
    padding-bottom: var(--space-3);
    margin-bottom: var(--space-3);
    border-bottom: 1px solid var(--nxt-light-3);
}

.mega-menu-header h3 {
    font-size: var(--text-base);
    font-weight: 700;
    color: var(--nxt-dark);
}

.mega-menu-header p {
    font-size: var(--text-xs);
    color: var(--nxt-gray-500);
    margin: 0;
}

.mega-menu-footer {
    padding-top: var(--space-3);
    margin-top: var(--space-3);
    border-top: 1px solid var(--nxt-light-3);
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.mega-menu-footer a {
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--nxt-blue-600);
    display: flex;
    align-items: center;
    gap: var(--space-1);
}

.mega-menu-footer a:hover {
    color: var(--nxt-blue-700);
}

/* Header Actions */
.header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    flex-shrink: 0;
}

.header-phone {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-sm);
    font-weight: 600;
    color: rgba(255, 255, 255, 0.9);
    transition: color var(--transition-fast);
}

.scrolled .header-phone {
    color: var(--nxt-dark);
}

.header-phone svg {
    width: 16px;
    height: 16px;
}

/* Mobile Menu Toggle */
.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    z-index: 10;
    padding: var(--space-2);
}

.mobile-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--nxt-white);
    border-radius: 2px;
    transition: all var(--transition-base);
}

.scrolled .mobile-toggle span {
    background: var(--nxt-dark);
}

.mobile-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-toggle.active span:nth-child(2) {
    opacity: 0;
}

.mobile-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Menu */
.mobile-menu-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, 0.5);
    backdrop-filter: blur(4px);
    z-index: var(--z-modal-backdrop);
}

.mobile-menu-overlay.active {
    display: block;
}

.mobile-menu {
    display: none;
    position: fixed;
    top: 0;
    right: -100%;
    width: 85%;
    max-width: 400px;
    height: 100vh;
    background: var(--nxt-white);
    z-index: var(--z-modal);
    padding: var(--space-20) var(--space-6) var(--space-6);
    overflow-y: auto;
    transition: right var(--transition-base);
}

.mobile-menu.active {
    right: 0;
}

.mobile-nav-item {
    border-bottom: 1px solid var(--nxt-light-3);
}

.mobile-nav-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) 0;
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--nxt-dark);
    min-height: 44px;
}

.mobile-nav-link svg {
    width: 20px;
    height: 20px;
    transition: transform var(--transition-fast);
}

.mobile-nav-item.open .mobile-nav-link svg {
    transform: rotate(180deg);
}

.mobile-submenu {
    display: none;
    padding-bottom: var(--space-4);
}

.mobile-nav-item.open .mobile-submenu {
    display: block;
}

.mobile-submenu a {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
    color: var(--nxt-gray-600);
    border-radius: var(--radius-md);
    min-height: 44px;
}

.mobile-submenu a:hover {
    background: var(--nxt-blue-50);
    color: var(--nxt-blue-600);
}

/* Mega menu edge-aware positioning for left-side nav items */
.nav-item:first-child .mega-menu,
.nav-item:nth-child(2) .mega-menu {
    left: 0;
    transform: translateX(0) translateY(10px);
}
.nav-item:first-child:hover .mega-menu,
.nav-item:nth-child(2):hover .mega-menu {
    transform: translateX(0) translateY(0);
}

/* Mega menu edge-aware positioning for right-side nav items */
.nav-item:nth-last-child(2) .mega-menu,
.nav-item:nth-last-child(3) .mega-menu {
    left: auto;
    right: 0;
    transform: translateX(0) translateY(10px);
}
.nav-item:nth-last-child(2):hover .mega-menu,
.nav-item:nth-last-child(3):hover .mega-menu {
    transform: translateX(0) translateY(0);
}

/* ========================================
   RESPONSIVE HEADER
   ======================================== */

/* Compact desktop: 1281px–1440px */
@media (min-width: 1281px) and (max-width: 1440px) {
    .header-inner {
        gap: var(--space-4);
    }
    .site-logo-img {
        height: 36px;
    }
    .nav-link {
        padding: var(--space-2) 6px;
        font-size: 0.75rem;
        gap: 2px;
    }
    .nav-link svg {
        width: 14px;
        height: 14px;
    }
    .mega-menu {
        min-width: 500px;
        max-width: min(540px, 90vw);
        padding: var(--space-3) var(--space-4);
    }
    .mega-menu-icon {
        width: 28px;
        height: 28px;
        min-width: 28px;
        font-size: 13px;
    }
    .mega-menu-content h4 {
        font-size: 0.75rem;
    }
    .mega-menu-content p {
        font-size: 0.625rem;
    }
    .mega-menu-header h3 {
        font-size: var(--text-sm);
    }
    .mega-menu-header p {
        font-size: 0.6875rem;
    }
    .mega-menu-item {
        padding: 5px var(--space-2);
        gap: 6px;
    }
    .mega-menu-header {
        padding-bottom: var(--space-2);
        margin-bottom: var(--space-2);
    }
    .mega-menu-footer {
        padding-top: var(--space-2);
        margin-top: var(--space-2);
    }
    .mega-menu-footer a {
        font-size: 0.6875rem;
    }
    .header-phone span {
        font-size: var(--text-xs);
    }
    .header-actions .btn {
        font-size: var(--text-xs);
        padding: var(--space-2) var(--space-3);
    }
}

/* Mobile breakpoint: 1280px */
@media (max-width: 1280px) {
    .main-nav {
        display: none;
    }
    .header-inner {
        gap: var(--space-3);
    }
    .site-logo-img {
        height: 36px;
    }
    .mobile-toggle {
        display: flex;
    }
    .mobile-menu {
        display: block;
    }
    .header-phone {
        display: none;
    }
}

@media (max-width: 480px) {
    .site-header {
        padding: var(--space-2) 0;
    }
    .header-inner {
        gap: var(--space-2);
    }
    .site-logo-img {
        height: 30px;
    }
    .header-actions .btn {
        padding: var(--space-2) var(--space-4);
        font-size: var(--text-xs);
        min-height: 44px;
    }
    .mobile-toggle {
        padding: var(--space-2);
        min-width: 44px;
        min-height: 44px;
        align-items: center;
        justify-content: center;
    }
}