/* =========================================================
   05. NAVIGATION
   ========================================================= */

.site-header {
    position: fixed;

    inset: 0 0 auto;

    z-index: 500;

    padding-block: 1.25rem;

    transition:
        background var(--duration-normal) var(--ease-standard),
        backdrop-filter var(--duration-normal) var(--ease-standard),
        border-color var(--duration-normal) var(--ease-standard);
}

.site-header.is-scrolled {
    background: rgba(5, 5, 7, 0.72);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid var(--color-line);
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.brand__mark {
    display: grid;
    place-items: center;

    width: 2.25rem;
    height: 2.25rem;

    border: 1px solid var(--color-line-strong);
    border-radius: 50%;

    font-family: var(--font-display);
    font-weight: 600;
}

.brand__text {
    display: flex;
    flex-direction: column;

    line-height: 1;
}

.brand__text strong {
    font-family: var(--font-display);
    font-size: 0.9rem;
    letter-spacing: 0.08em;
}

.brand__text small {
    margin-top: 0.25rem;

    color: var(--color-text-muted);

    font-size: 0.55rem;
    letter-spacing: 0.18em;
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.site-nav a {
    position: relative;

    color: var(--color-text-muted);

    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;

    transition: color var(--duration-fast) ease;
}

.site-nav a::after {
    content: "";

    position: absolute;
    left: 0;
    bottom: -0.4rem;

    width: 100%;
    height: 1px;

    background: currentColor;

    transform: scaleX(0);
    transform-origin: right;

    transition: transform var(--duration-normal) var(--ease-standard);
}

.site-nav a:hover {
    color: var(--color-white);
}

.site-nav a:hover::after {
    transform: scaleX(1);
    transform-origin: left;
}

.site-header__actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.motion-toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;

    color: var(--color-text-muted);

    font-size: 0.65rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.motion-toggle__dot {
    width: 6px;
    height: 6px;

    border-radius: 50%;
    background: currentColor;
}

.menu-toggle {
    display: none;

    width: 2.5rem;
    height: 2.5rem;
}

/* NOTE: bar styling for .menu-toggle is now defined in
   css/25-menu-toggle-universal.css (the shared ServoraPrise
   hamburger → "+" component, sourced from experience.html).
   Do not re-add span rules here — it will conflict. */

/* When the mobile menu is open the header must fill the
   viewport. backdrop-filter otherwise traps position:fixed
   children inside the short header bar. */
body.menu-open {
    overflow: hidden;
}

body.menu-open .site-header {
    inset: 0;
    height: 100dvh;
    height: 100%;
    background: rgba(5, 5, 7, 0.97);
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    border-bottom: none;
}

body.menu-open .site-header__inner {
    position: relative;
    z-index: 3;
}

body.menu-open .menu-toggle {
    z-index: 4;
}