/* ==========================================================================
   VLab-4000 — Header & Navigation
   ========================================================================== */

/* =========================================================================
   SITE HEADER
   ========================================================================= */

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-header);
    background-color: var(--white);
    border-bottom: 1px solid transparent;
    transition:
        border-color var(--transition-normal),
        box-shadow var(--transition-normal),
        background-color var(--transition-normal);
    height: 72px;
    display: flex;
    align-items: center;
}

/* Scrolled state — JS adds this class */
.site-header.is-scrolled {
    box-shadow: 0 2px 16px rgba(43, 45, 66, 0.1);
    border-bottom-color: var(--color-border-light);
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-24);
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-24);
    height: 100%;
}

/* =========================================================================
   LOGO
   ========================================================================= */

.site-header__logo {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    gap: var(--space-12);
    text-decoration: none;
    color: var(--color-primary);
    transition: opacity var(--transition-fast);
}

.site-header__logo:hover {
    opacity: 0.85;
    text-decoration: none;
    color: var(--color-primary);
}

.site-header__logo-image {
    height: 36px;
    width: auto;
    display: block;
}

.site-header__logo-text {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: var(--weight-extrabold);
    color: var(--color-primary);
    letter-spacing: -0.02em;
    line-height: 1;
}

.site-header__logo-text span {
    color: var(--color-accent);
}

/* =========================================================================
   MAIN NAVIGATION
   ========================================================================= */

.main-nav {
    display: none;
    align-items: center;
    gap: var(--space-4);
    list-style: none;
    padding: 0;
    margin: 0;
    height: 100%;
}

@media (min-width: 1024px) {
    .main-nav {
        display: flex;
    }
}

.main-nav__item {
    position: relative;
    height: 100%;
    display: flex;
    align-items: center;
}

.main-nav__link {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    padding: var(--space-8) var(--space-12);
    font-family: var(--font-body);
    font-size: var(--text-body);
    font-weight: var(--weight-medium);
    color: var(--ink-700);
    text-decoration: none;
    border-radius: var(--radius-md);
    white-space: nowrap;
    transition:
        color var(--transition-fast),
        background-color var(--transition-fast);
    position: relative;
}

/* Hover underline — Arterial Red */
.main-nav__link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: var(--space-12);
    right: var(--space-12);
    height: 2px;
    background-color: var(--color-accent);
    border-radius: var(--radius-pill);
    transform: scaleX(0);
    transition: transform var(--transition-normal);
    transform-origin: left center;
}

.main-nav__link:hover {
    color: var(--color-accent);
    text-decoration: none;
    background-color: var(--color-accent-subtle);
}

.main-nav__link:hover::after {
    transform: scaleX(1);
}

/* Active link */
.main-nav__link.is-active {
    color: var(--color-accent);
    font-weight: var(--weight-semibold);
}

.main-nav__link.is-active::after {
    transform: scaleX(1);
}

/* Chevron for dropdown triggers */
.main-nav__chevron {
    width: 14px;
    height: 14px;
    transition: transform var(--transition-fast);
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.main-nav__item:hover .main-nav__chevron {
    transform: rotate(180deg);
}

/* =========================================================================
   DROPDOWN MENU
   ========================================================================= */

.nav-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    min-width: 240px;
    background-color: var(--white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-elevated);
    z-index: var(--z-dropdown);
    padding: var(--space-8);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition:
        opacity var(--transition-fast),
        visibility var(--transition-fast),
        transform var(--transition-fast);
    pointer-events: none;
}

.main-nav__item:hover .nav-dropdown,
.main-nav__item:focus-within .nav-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
}

.nav-dropdown__link {
    display: flex;
    align-items: center;
    gap: var(--space-12);
    padding: var(--space-10, 0.625rem) var(--space-12);
    font-size: var(--text-body);
    font-weight: var(--weight-regular);
    color: var(--ink-700);
    text-decoration: none;
    border-radius: var(--radius-md);
    transition:
        background-color var(--transition-fast),
        color var(--transition-fast);
    white-space: nowrap;
}

.nav-dropdown__link:hover {
    background-color: var(--color-accent-subtle);
    color: var(--color-accent);
    text-decoration: none;
}

.nav-dropdown__link-icon {
    width: 20px;
    height: 20px;
    color: var(--ink-300);
    flex-shrink: 0;
    transition: color var(--transition-fast);
}

.nav-dropdown__link:hover .nav-dropdown__link-icon {
    color: var(--color-accent);
}

.nav-dropdown__divider {
    height: 1px;
    background-color: var(--color-border);
    margin: var(--space-8) 0;
    border: none;
}

.nav-dropdown__group-title {
    font-family: var(--font-heading);
    font-size: var(--text-micro);
    font-weight: var(--weight-semibold);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--ink-300);
    padding: var(--space-8) var(--space-12) var(--space-4);
}

/* =========================================================================
   LANGUAGE SWITCHER
   ========================================================================= */

.lang-switcher {
    position: relative;
    display: none;
    align-items: center;
}

@media (min-width: 768px) {
    .lang-switcher {
        display: flex;
    }
}

.lang-switcher__trigger {
    display: flex;
    align-items: center;
    gap: var(--space-6, 0.375rem);
    padding: var(--space-8) var(--space-12);
    font-family: var(--font-body);
    font-size: var(--text-small);
    font-weight: var(--weight-medium);
    color: var(--ink-700);
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition:
        border-color var(--transition-fast),
        color var(--transition-fast),
        background-color var(--transition-fast);
    min-height: 36px;
}

.lang-switcher__trigger:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    background-color: var(--color-bg-alt);
}

.lang-switcher__flag {
    width: 18px;
    height: 13px;
    border-radius: 2px;
    flex-shrink: 0;
    object-fit: cover;
}

.lang-switcher__chevron {
    width: 12px;
    height: 12px;
    transition: transform var(--transition-fast);
    stroke: currentColor;
    fill: none;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.lang-switcher:hover .lang-switcher__chevron,
.lang-switcher__trigger[aria-expanded="true"] .lang-switcher__chevron {
    transform: rotate(180deg);
}

.lang-dropdown {
    position: absolute;
    top: calc(100% + 6px);
    right: 0;
    min-width: 140px;
    background-color: var(--white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-elevated);
    z-index: var(--z-dropdown);
    padding: var(--space-8);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition:
        opacity var(--transition-fast),
        visibility var(--transition-fast),
        transform var(--transition-fast);
}

.lang-switcher:hover .lang-dropdown,
.lang-switcher__trigger[aria-expanded="true"] + .lang-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lang-dropdown__option {
    display: flex;
    align-items: center;
    gap: var(--space-10, 0.625rem);
    padding: var(--space-8) var(--space-12);
    font-size: var(--text-small);
    font-weight: var(--weight-regular);
    color: var(--ink-700);
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: background-color var(--transition-fast), color var(--transition-fast);
    white-space: nowrap;
}

.lang-dropdown__option:hover {
    background-color: var(--color-bg-alt);
    color: var(--color-primary);
    text-decoration: none;
}

.lang-dropdown__option.is-active {
    color: var(--color-accent);
    font-weight: var(--weight-semibold);
}

/* =========================================================================
   HEADER ACTIONS (CTA area)
   ========================================================================= */

.site-header__actions {
    display: none;
    align-items: center;
    gap: var(--space-12);
    flex-shrink: 0;
}

@media (min-width: 768px) {
    .site-header__actions {
        display: flex;
    }
}

/* =========================================================================
   MOBILE HAMBURGER
   ========================================================================= */

.hamburger {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    border: none;
    background: transparent;
    cursor: pointer;
    padding: var(--space-8);
    border-radius: var(--radius-md);
    transition: background-color var(--transition-fast);
    flex-shrink: 0;
}

.hamburger:hover {
    background-color: var(--color-bg-alt);
}

.hamburger:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

/* Three lines */
.hamburger__bar {
    display: block;
    width: 22px;
    height: 2px;
    background-color: var(--color-primary);
    border-radius: var(--radius-pill);
    transition:
        transform var(--transition-normal),
        opacity var(--transition-fast),
        width var(--transition-normal);
    transform-origin: center;
}

/* Animated X state */
.hamburger[aria-expanded="true"] .hamburger__bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.hamburger[aria-expanded="true"] .hamburger__bar:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}

.hamburger[aria-expanded="true"] .hamburger__bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* Hide hamburger on desktop */
@media (min-width: 1024px) {
    .hamburger {
        display: none;
    }
}

/* =========================================================================
   MOBILE NAV DRAWER
   ========================================================================= */

.mobile-nav {
    position: fixed;
    top: 72px; /* header height */
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--white);
    z-index: calc(var(--z-header) - 1);
    overflow-y: auto;
    padding: var(--space-24);
    transform: translateX(100%);
    transition: transform var(--transition-normal);
    border-top: 1px solid var(--color-border);
}

.mobile-nav.is-open {
    transform: translateX(0);
}

/* Mobile nav overlay */
.mobile-nav-overlay {
    position: fixed;
    inset: 72px 0 0 0;
    background-color: rgba(43, 45, 66, 0.5);
    z-index: calc(var(--z-header) - 2);
    opacity: 0;
    visibility: hidden;
    transition:
        opacity var(--transition-normal),
        visibility var(--transition-normal);
}

.mobile-nav-overlay.is-visible {
    opacity: 1;
    visibility: visible;
}

/* Mobile nav links */
.mobile-nav__list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.mobile-nav__item {
    border-bottom: 1px solid var(--color-border-light);
}

.mobile-nav__link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-16) var(--space-4);
    font-family: var(--font-heading);
    font-size: var(--text-body);
    font-weight: var(--weight-semibold);
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.mobile-nav__link:hover {
    color: var(--color-accent);
    text-decoration: none;
}

.mobile-nav__link.is-active {
    color: var(--color-accent);
}

/* Mobile sub-links */
.mobile-nav__sub {
    list-style: none;
    padding: 0 0 var(--space-8) var(--space-20);
    margin: 0;
}

.mobile-nav__sub-link {
    display: block;
    padding: var(--space-10, 0.625rem) var(--space-8);
    font-size: var(--text-body);
    font-weight: var(--weight-regular);
    color: var(--ink-500);
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: color var(--transition-fast), background-color var(--transition-fast);
}

.mobile-nav__sub-link:hover {
    color: var(--color-accent);
    background-color: var(--color-accent-subtle);
    text-decoration: none;
}

.mobile-nav__actions {
    display: flex;
    flex-direction: column;
    gap: var(--space-12);
    margin-top: var(--space-32);
    padding-top: var(--space-24);
    border-top: 2px solid var(--color-border);
}

.mobile-nav__lang {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-8);
    padding-top: var(--space-16);
}

/* Hide mobile nav above 1024px */
@media (min-width: 1024px) {
    .mobile-nav,
    .mobile-nav-overlay {
        display: none !important;
    }
}