/* ==========================================================================
   KROTAR — Header & Navigation
   ========================================================================== */

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: var(--z-header);
    padding: 0.85rem 0;
    background: rgba(2, 3, 6, 0);
    border-bottom: 1px solid rgba(255, 255, 255, 0);
    backdrop-filter: blur(0px);
    -webkit-backdrop-filter: blur(0px);
    transition: background var(--duration-base) var(--ease-premium),
        border-color var(--duration-base) var(--ease-premium),
        backdrop-filter var(--duration-base) var(--ease-premium),
        padding var(--duration-base) var(--ease-premium);
}

.site-header.is-scrolled {
    padding: 0.6rem 0;
    background: rgba(2, 3, 6, 0.72);
    border-bottom: 1px solid var(--color-border);
    backdrop-filter: blur(18px) saturate(160%);
    -webkit-backdrop-filter: blur(18px) saturate(160%);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-5);
}

.site-logo {
    display: inline-flex;
    align-items: center;
    text-decoration: none;
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.15rem;
    letter-spacing: 0.14em;
    color: var(--color-text);
    user-select: none;
}

.site-logo span {
    color: var(--color-cyan);
}

.main-nav {
    display: flex;
    align-items: center;
    gap: var(--space-6);
}

.main-nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-5);
    list-style: none;
}

.main-nav-links a {
    font-size: 0.92rem;
    font-weight: 500;
    color: var(--color-text-body);
    text-decoration: none;
    letter-spacing: 0.01em;
    padding: 0.4rem 0.1rem;
    position: relative;
    transition: color var(--duration-fast) ease;
}

.main-nav-links a::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -2px;
    width: 0%;
    height: 1px;
    background: var(--color-cyan);
    transition: width var(--duration-base) var(--ease-premium);
}

.main-nav-links a:hover {
    color: var(--color-text);
}

.main-nav-links a:hover::after {
    width: 100%;
}

.main-nav-links a.is-active {
    color: var(--color-text);
}

.main-nav-links a.is-active::after {
    width: 100%;
    background: var(--color-cyan);
}

.header-cta {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-sm);
    z-index: var(--z-mobile-nav);
}

.nav-toggle-bar {
    display: block;
    width: 18px;
    height: 1.5px;
    margin: 0 auto;
    background: var(--color-text);
    transition: transform var(--duration-base) var(--ease-premium), opacity var(--duration-fast) ease;
}

.nav-toggle.is-open .nav-toggle-bar:nth-child(1) {
    transform: translateY(6.5px) rotate(45deg);
}

.nav-toggle.is-open .nav-toggle-bar:nth-child(2) {
    opacity: 0;
}

.nav-toggle.is-open .nav-toggle-bar:nth-child(3) {
    transform: translateY(-6.5px) rotate(-45deg);
}

/* ==========================================================================
   Mobile navigation
   ========================================================================== */
@media (max-width: 860px) {
    .main-nav-links {
        position: fixed;
        inset: 0 0 0 auto;
        width: min(78vw, 340px);
        height: 100vh;
        flex-direction: column;
        align-items: flex-start;
        justify-content: center;
        gap: var(--space-5);
        padding: var(--space-8) var(--space-6);
        background: rgba(3, 4, 9, 0.97);
        backdrop-filter: blur(24px);
        -webkit-backdrop-filter: blur(24px);
        border-left: 1px solid var(--color-border);
        transform: translateX(100%);
        transition: transform var(--duration-base) var(--ease-premium);
        z-index: var(--z-mobile-nav);
    }

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

    .main-nav-links a {
        font-size: 1.05rem;
    }

    .nav-toggle {
        display: flex;
    }
}

@media (max-width: 480px) {
    .header-cta .btn span {
        display: none;
    }

    .header-cta .btn {
        padding: 12px 16px;
    }
}

.nav-scrim {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--duration-base) ease;
    /* Must stay below .site-header (z-index: var(--z-header), 50). .site-header
       is itself a stacking context, so a scrim z-index higher than the
       header's own (as 55 was) renders above the ENTIRE header — including
       .main-nav-links inside it — regardless of the nav's higher internal
       z-index (60), silently swallowing every click on the mobile menu. */
    z-index: 40;
}

.nav-scrim.is-open {
    opacity: 1;
    pointer-events: auto;
}