/* ==========================================================================
   Variation B "Cinematic Spec" -- Header Styles
   ==========================================================================
   Translucent over the hero scene, becomes solid Deep Navy on scroll past
   the hero. The header is the page's opening transition -- invisible chrome
   over the cinema, then chrome reasserts itself on the scrolled state.

   Class state:
     .site-header--over-hero (initial, transparent over hero panel)
     .site-header--scrolled  (after scroll past 50vh, solid #0A1628)

   Toggled by initCinematicHeader() in main.js based on
   IntersectionObserver against the hero panel boundary.

   Mobile: the over-hero state is preserved at <768px, but the hamburger
   becomes more prominent and the login CTA hides into the drawer.
   ========================================================================== */


/* --------------------------------------------------------------------------
   Body offset -- no padding-top, header sits OVER hero
   -------------------------------------------------------------------------- */

body.has-cinematic-header {
    /* No top padding. Header is fixed-position over the hero panel. */
    padding-top: 0;
}


/* --------------------------------------------------------------------------
   Site Header (Cinematic)
   -------------------------------------------------------------------------- */

.site-header--cinematic {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-sticky);
    background-color: transparent;
    border-bottom: 1px solid rgba(232, 238, 245, 0.04);
    transition:
        background-color var(--transition-cinematic) var(--ease-out),
        border-bottom-color var(--transition-cinematic) var(--ease-out),
        box-shadow var(--transition-cinematic) var(--ease-out),
        backdrop-filter var(--transition-cinematic) var(--ease-out);
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
}

.site-header--cinematic .site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-2xl);
    min-height: 88px;
    padding: var(--space-md) 0;
}


/* --------------------------------------------------------------------------
   Scrolled state -- solid Deep Navy, hairline visible, subtle shadow
   -------------------------------------------------------------------------- */

.site-header--cinematic.site-header--scrolled {
    background-color: rgba(10, 22, 40, 0.92);
    border-bottom-color: rgba(232, 238, 245, 0.12);
    box-shadow: 0 4px 20px rgba(5, 11, 24, 0.4);
    -webkit-backdrop-filter: blur(12px) saturate(1.1);
    backdrop-filter: blur(12px) saturate(1.1);
}

.site-header--cinematic.site-header--scrolled .site-header__inner {
    min-height: 72px;
}


/* --------------------------------------------------------------------------
   Logo
   -------------------------------------------------------------------------- */

.site-header__brand {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.site-header__logo-link {
    display: inline-flex;
    align-items: center;
    text-decoration: none;
    transition: opacity var(--transition-base) var(--ease-out);
}

.site-header__logo-link:hover,
.site-header__logo-link:focus-visible {
    opacity: 0.85;
    outline: none;
}

.site-header__logo-link:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 4px;
    border-radius: var(--radius-sm);
}

.site-header__logo {
    height: 44px;
    width: auto;
    display: block;
    filter: drop-shadow(0 2px 8px rgba(5, 11, 24, 0.5));
    transition: filter var(--transition-cinematic) var(--ease-out);
}

.site-header--scrolled .site-header__logo {
    /* Less drop-shadow when on solid bg -- shadow was for legibility over imagery */
    filter: drop-shadow(0 1px 3px rgba(5, 11, 24, 0.3));
}


/* --------------------------------------------------------------------------
   Primary Navigation
   -------------------------------------------------------------------------- */

.site-header__nav {
    flex: 1 1 auto;
    display: flex;
    justify-content: center;
}

.site-header__menu {
    display: flex;
    align-items: center;
    gap: var(--space-xl);
    margin: 0;
    padding: 0;
    list-style: none;
}

.site-header__menu-item {
    margin: 0;
    padding: 0;
}

.site-header__menu-link {
    display: inline-flex;
    align-items: center;
    padding: var(--space-sm) var(--space-xs);
    font-family: var(--font-body);
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    text-decoration: none;
    color: var(--text-primary);
    text-shadow: 0 1px 4px rgba(5, 11, 24, 0.4);
    transition:
        color var(--transition-base) var(--ease-out),
        text-shadow var(--transition-cinematic) var(--ease-out),
        opacity var(--transition-base) var(--ease-out);
    position: relative;
    opacity: 0.95;
}

.site-header--scrolled .site-header__menu-link {
    text-shadow: none;
}

.site-header__menu-link::after {
    content: '';
    position: absolute;
    left: var(--space-xs);
    right: var(--space-xs);
    bottom: 4px;
    height: 1px;
    background-color: var(--color-accent);
    transform: scaleX(0);
    transform-origin: left center;
    transition: transform var(--transition-base) var(--ease-out);
}

.site-header__menu-link:hover,
.site-header__menu-link:focus-visible {
    color: var(--color-accent-light);
    opacity: 1;
    outline: none;
}

.site-header__menu-link:hover::after,
.site-header__menu-link:focus-visible::after {
    transform: scaleX(1);
}


/* --------------------------------------------------------------------------
   Header Actions (Login + Hamburger)
   -------------------------------------------------------------------------- */

.site-header__actions {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    flex-shrink: 0;
}

.site-header__login {
    /* Inherits .btn .btn--ghost .btn--sm from design-system.css. */
    /* Slight extra translucent treatment over hero so it reads on imagery. */
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    border-color: rgba(232, 238, 245, 0.45);
    background-color: rgba(10, 22, 40, 0.25);
    transition:
        background-color var(--transition-base) var(--ease-out),
        border-color var(--transition-base) var(--ease-out),
        color var(--transition-base) var(--ease-out),
        transform var(--transition-base) var(--ease-out);
}

.site-header--scrolled .site-header__login {
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    background-color: transparent;
    border-color: rgba(232, 238, 245, 0.35);
}

.site-header__login:hover,
.site-header__login:focus-visible {
    background-color: rgba(0, 102, 204, 0.15);
    border-color: var(--color-accent);
    color: var(--color-accent-light);
    transform: translateY(-1px);
    outline: none;
}


/* --------------------------------------------------------------------------
   Mobile Menu Toggle (Hamburger)
   -------------------------------------------------------------------------- */

.site-header__menu-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    padding: 0;
    background-color: transparent;
    border: 1px solid rgba(232, 238, 245, 0.18);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: border-color var(--transition-base) var(--ease-out);
}

.site-header__menu-toggle:hover,
.site-header__menu-toggle:focus-visible {
    border-color: var(--color-accent);
    outline: none;
}

.site-header__hamburger {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 24px;
    height: 18px;
    gap: 4px;
}

.site-header__hamburger-line {
    width: 100%;
    height: 1px;
    background-color: var(--text-primary);
    transition: transform var(--transition-base) var(--ease-out),
                opacity var(--transition-base) var(--ease-out);
}


/* --------------------------------------------------------------------------
   Mobile Menu (Drawer)
   -------------------------------------------------------------------------- */

.mobile-menu {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: var(--z-modal);
    pointer-events: none;
    visibility: hidden;
    overflow: hidden;
    transition: visibility 0s linear var(--transition-base);
}

.mobile-menu[aria-hidden="false"] {
    pointer-events: auto;
    visibility: visible;
    transition-delay: 0s;
}

.mobile-menu__overlay {
    position: absolute;
    inset: 0;
    background-color: rgba(5, 11, 24, 0.85);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    opacity: 0;
    transition: opacity var(--transition-base) var(--ease-out);
}

.mobile-menu[aria-hidden="false"] .mobile-menu__overlay {
    opacity: 1;
}

.mobile-menu__panel {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    width: min(100%, 420px);
    background-color: var(--bg-primary);
    border-left: 1px solid var(--border-color);
    box-shadow: -10px 0 40px rgba(5, 11, 24, 0.6);
    padding: var(--space-2xl);
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
    transform: translateX(100%);
    transition: transform var(--transition-slow) var(--ease-spring);
}

.mobile-menu[aria-hidden="false"] .mobile-menu__panel {
    transform: translateX(0);
}

.mobile-menu__close {
    align-self: flex-end;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    color: var(--text-primary);
    background-color: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: border-color var(--transition-base) var(--ease-out),
                color var(--transition-base) var(--ease-out);
}

.mobile-menu__close:hover,
.mobile-menu__close:focus-visible {
    border-color: var(--color-accent);
    color: var(--color-accent);
    outline: none;
}

.mobile-menu__nav {
    margin-top: var(--space-md);
}

.mobile-menu__list {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
    margin: 0;
    padding: 0;
    list-style: none;
}

.mobile-menu__item {
    margin: 0;
    padding: 0;
}

.mobile-menu__link {
    display: block;
    padding: var(--space-md) 0;
    font-family: var(--font-heading);
    font-size: var(--text-2xl);
    font-weight: 200;
    letter-spacing: var(--tracking-tight);
    color: var(--text-primary);
    text-decoration: none;
    border-bottom: 1px solid var(--border-color);
    transition: color var(--transition-base) var(--ease-out),
                border-bottom-color var(--transition-base) var(--ease-out),
                padding-left var(--transition-base) var(--ease-out);
}

.mobile-menu__link:hover,
.mobile-menu__link:focus-visible {
    color: var(--color-accent-light);
    border-bottom-color: var(--color-accent);
    padding-left: var(--space-sm);
    outline: none;
}

.mobile-menu__cta {
    margin-top: auto;
    padding-top: var(--space-xl);
    border-top: 1px solid var(--border-color);
}


/* --------------------------------------------------------------------------
   Skip Link (Accessibility)
   -------------------------------------------------------------------------- */

.skip-link {
    position: absolute;
    left: -9999px;
    top: 0;
    background-color: var(--color-accent);
    color: #ffffff;
    padding: var(--space-md) var(--space-lg);
    z-index: var(--z-max);
    text-decoration: none;
    font-weight: var(--font-medium);
    border-radius: 0 0 var(--radius-md) 0;
}

.skip-link:focus {
    left: 0;
}

.sr-only:not(:focus):not(:active) {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}


/* --------------------------------------------------------------------------
   Body scroll lock (when mobile menu is open)
   -------------------------------------------------------------------------- */

body.menu-open {
    overflow: hidden;
}


/* --------------------------------------------------------------------------
   Responsive -- Tablet & Mobile
   -------------------------------------------------------------------------- */

@media (max-width: 1024px) {
    .site-header__menu {
        gap: var(--space-lg);
    }

    .site-header__menu-link {
        font-size: var(--text-xs);
    }
}

@media (max-width: 768px) {
    .site-header--cinematic .site-header__inner {
        min-height: 72px;
    }

    .site-header--cinematic.site-header--scrolled .site-header__inner {
        min-height: 64px;
    }

    .site-header__nav {
        display: none;
    }

    .site-header__login {
        display: none;
    }

    .site-header__menu-toggle {
        display: inline-flex;
    }

    .site-header__logo {
        height: 36px;
    }
}


/* --------------------------------------------------------------------------
   Reduced Motion
   -------------------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
    .site-header--cinematic,
    .site-header--cinematic .site-header__inner,
    .site-header--cinematic .site-header__menu-link,
    .site-header--cinematic .site-header__menu-link::after,
    .site-header--cinematic .site-header__login,
    .site-header--cinematic .site-header__logo,
    .mobile-menu__overlay,
    .mobile-menu__panel,
    .mobile-menu__link {
        transition-duration: 0ms !important;
    }
}