/* ============================================================
   Navigation
   Header, persistent desktop nav, hamburger + mobile panel,
   audio toggle, and the bottom progress navigator (rail).
   ============================================================ */

/* ---------- Header shell ---------- */
.museum-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-header);
    height: var(--header-height);
    padding: 0 var(--page-pad);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
    pointer-events: none;
}

.logo,
.nav-inline,
.header-actions,
.nav-trigger,
.nav-menu {
    pointer-events: auto;
}

/* ---------- Logo ---------- */
.logo {
    display: inline-flex;
    align-items: center;
    gap: 0.85rem;
    flex-shrink: 0;
    text-decoration: none;
}

.logo-symbol {
    width: 2.25rem;
    height: 2.25rem;
    display: grid;
    place-items: center;
    border: 1px solid rgba(255, 255, 255, 0.82);
    border-radius: 50%;
    color: rgba(255, 255, 255, 0.95);
    font-family: var(--font-display);
    font-size: 1.7rem;
    line-height: 1;
    transition: border-color var(--duration-fast), box-shadow var(--duration-fast);
}

.logo:hover .logo-symbol {
    border-color: #fff;
    box-shadow: 0 0 22px rgba(255, 255, 255, 0.25);
}

.logo-text {
    color: var(--color-muted);
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    letter-spacing: 0.26em;
    text-transform: uppercase;
    transition: color var(--duration-fast);
}

.logo:hover .logo-text {
    color: var(--color-text);
}

/* ---------- Persistent desktop navigation ---------- */
.nav-inline {
    display: flex;
    align-items: center;
    gap: clamp(1.25rem, 2.4vw, 2.75rem);
}

.nav-inline .nav-link {
    position: relative;
    display: inline-flex;
    align-items: baseline;
    gap: 0.5rem;
    padding: 0.4rem 0;
    color: var(--color-faint);
    text-decoration: none;
    font-family: var(--font-mono);
    text-transform: uppercase;
    transition: color var(--duration-fast);
}

.nav-inline .nav-number {
    font-size: 0.6rem;
    letter-spacing: 0.18em;
    opacity: 0.7;
}

.nav-inline .nav-name {
    font-size: var(--text-xs);
    letter-spacing: 0.2em;
}

.nav-inline .nav-link::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 1px;
    background: var(--color-text);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--duration) var(--ease-out);
}

.nav-inline .nav-link:hover,
.nav-inline .nav-link.active {
    color: var(--color-text);
}

.nav-inline .nav-link:hover::after,
.nav-inline .nav-link.active::after {
    transform: scaleX(1);
}

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

/* ---------- Audio toggle ---------- */
.audio-toggle {
    position: relative;
    width: 2.6rem;
    height: 2.6rem;
    border: 1px solid var(--color-line);
    border-radius: 50%;
    display: grid;
    place-items: center;
    transition: border-color var(--duration-fast), background var(--duration-fast);
}

.audio-toggle span {
    width: 0.55rem;
    height: 0.55rem;
    border-radius: 50%;
    background: var(--color-faint);
    box-shadow: 0 0 0 rgba(255, 255, 255, 0);
    transition: background var(--duration-fast), box-shadow var(--duration-fast);
}

.audio-toggle:hover {
    border-color: rgba(255, 255, 255, 0.5);
}

.audio-toggle.active,
.audio-toggle[aria-pressed="true"] {
    border-color: rgba(255, 255, 255, 0.5);
}

.audio-toggle.active span,
.audio-toggle[aria-pressed="true"] span {
    background: var(--color-text);
    box-shadow: 0 0 18px rgba(255, 255, 255, 0.5);
}

/* ---------- Hamburger trigger (mobile / tablet) ---------- */
.nav-trigger {
    position: relative;
    z-index: calc(var(--z-nav) + 1);
    width: 3rem;
    height: 3rem;
    display: none;
    place-items: center;
    border-radius: 50%;
    transition: background var(--duration-fast);
}

.nav-trigger:hover {
    background: rgba(255, 255, 255, 0.06);
}

.nav-line {
    display: block;
    position: absolute;
    top: 50%;
    left: 50%;
    width: 1.6rem;
    height: 1.5px;
    margin: 0;
    background: rgba(255, 255, 255, 0.92);
    border-radius: 2px;
    transform-origin: center;
    transition: transform var(--duration) var(--ease-out), opacity var(--duration-fast), width var(--duration-fast);
}

.nav-line:nth-child(1) { transform: translate(-50%, calc(-50% - 0.42rem)); }
.nav-line:nth-child(2) { transform: translate(-50%, -50%); }
.nav-line:nth-child(3) { transform: translate(-50%, calc(-50% + 0.42rem)); }

.nav-trigger:hover .nav-line { width: 1.85rem; }

.nav-trigger.active .nav-line:nth-child(1) {
    transform: translate(-50%, -50%) rotate(45deg);
}
.nav-trigger.active .nav-line:nth-child(2) {
    opacity: 0;
}
.nav-trigger.active .nav-line:nth-child(3) {
    transform: translate(-50%, -50%) rotate(-45deg);
}

/* ---------- Mobile slide-in menu ---------- */
.nav-menu {
    position: fixed;
    top: 0;
    right: 0;
    z-index: var(--z-nav);
    width: min(100vw, 26rem);
    height: 100vh;
    padding: calc(var(--header-height) + var(--space-5)) var(--page-pad) var(--space-6);
    display: flex;
    flex-direction: column;
    gap: 0;
    background: rgba(4, 4, 4, 0.92);
    border-left: 1px solid var(--color-line-soft);
    backdrop-filter: blur(28px);
    -webkit-backdrop-filter: blur(28px);
    transform: translateX(100%);
    visibility: hidden;
    transition: transform 720ms var(--ease-out), visibility 0s linear 720ms;
}

.nav-menu.active {
    transform: translateX(0);
    visibility: visible;
    transition: transform 720ms var(--ease-out), visibility 0s;
}

.nav-menu .nav-link {
    position: relative;
    display: grid;
    grid-template-columns: 3.25rem 1fr;
    align-items: baseline;
    gap: var(--space-3);
    padding: 1.15rem 0;
    color: var(--color-faint);
    text-decoration: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    opacity: 0;
    transform: translateX(1.5rem);
    transition: color var(--duration-fast), opacity 560ms var(--ease-out), transform 560ms var(--ease-out);
}

.nav-menu.active .nav-link {
    opacity: 1;
    transform: translateX(0);
}

.nav-menu.active .nav-link:nth-child(1) { transition-delay: 90ms; }
.nav-menu.active .nav-link:nth-child(2) { transition-delay: 150ms; }
.nav-menu.active .nav-link:nth-child(3) { transition-delay: 210ms; }
.nav-menu.active .nav-link:nth-child(4) { transition-delay: 270ms; }
.nav-menu.active .nav-link:nth-child(5) { transition-delay: 330ms; }
.nav-menu.active .nav-link:nth-child(6) { transition-delay: 390ms; }

.nav-menu .nav-number {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    letter-spacing: 0.3em;
    color: inherit;
    opacity: 0.7;
}

.nav-menu .nav-name {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    letter-spacing: 0.34em;
    text-transform: uppercase;
}

.nav-menu .nav-link::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -1px;
    width: 100%;
    height: 1px;
    background: var(--color-text);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--duration) var(--ease-out);
}

.nav-menu .nav-link:hover,
.nav-menu .nav-link.active {
    color: var(--color-text);
}

.nav-menu .nav-link:hover::after,
.nav-menu .nav-link.active::after {
    transform: scaleX(1);
}

/* ============================================================
   Bottom progress navigator (rail)
   ============================================================ */
.room-rail {
    position: fixed;
    left: var(--page-pad);
    right: var(--page-pad);
    bottom: 2.2rem;
    z-index: var(--z-rail);
    height: 4.2rem;
    display: grid;
    grid-template-columns: 1fr auto;
    align-items: end;
    gap: var(--space-4);
    pointer-events: none;
}

.rail-track {
    position: absolute;
    top: 0.26rem;
    left: calc(100% / 12);
    right: calc(100% / 12);
    height: 1px;
    background: linear-gradient(90deg, rgba(255, 255, 255, 0.16), rgba(255, 255, 255, 0.06));
}

.rail-fill {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 0;
    background: linear-gradient(90deg, rgba(255, 255, 255, 0.55), rgba(255, 255, 255, 0.95));
    box-shadow: 0 0 14px rgba(255, 255, 255, 0.3);
    transition: width 760ms var(--ease-out);
}

.indicators {
    position: relative;
    height: 100%;
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    align-items: start;
}

.indicator {
    position: relative;
    min-width: 0;
    display: grid;
    justify-items: center;
    gap: 0.6rem;
    padding: 0;
    color: var(--color-faint);
    text-align: center;
    pointer-events: auto;
    transition: color var(--duration-fast);
}

.indicator::before {
    content: "";
    width: 0.5rem;
    height: 0.5rem;
    border: 1px solid currentColor;
    border-radius: 50%;
    background: #000;
    box-shadow: 0 0 0 rgba(255, 255, 255, 0);
    transition: background var(--duration-fast), border-color var(--duration-fast), box-shadow var(--duration-fast), transform var(--duration-fast);
}

.indicator-num,
.indicator small {
    font-family: var(--font-mono);
    text-transform: uppercase;
}

.indicator-num {
    font-size: var(--text-sm);
    letter-spacing: 0.22em;
    line-height: 1;
}

.indicator small {
    color: inherit;
    font-size: var(--text-xs);
    letter-spacing: 0.34em;
}

.indicator:hover,
.indicator.active {
    color: var(--color-text);
}

.indicator:hover::before,
.indicator.active::before {
    background: #fff;
    box-shadow: 0 0 22px rgba(255, 255, 255, 0.45);
}

.indicator:hover::before {
    transform: scale(1.25);
}

.indicator.active::before {
    border-color: #fff;
}

/* Current room readout, sits to the right of the rail */
.progress-current {
    align-self: end;
    justify-self: end;
    padding-bottom: 0.2rem;
    color: var(--color-muted);
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    letter-spacing: 0.28em;
    white-space: nowrap;
}

.progress-current #progress-current {
    color: var(--color-text);
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 1024px) {
    .nav-inline {
        display: none;
    }

    .nav-trigger {
        display: grid;
    }
}

@media (max-width: 760px) {
    .museum-header {
        padding: 0 var(--space-4);
    }

    .logo-text {
        display: none;
    }

    .nav-menu {
        width: 100vw;
        padding-inline: var(--space-5);
    }

    .room-rail {
        left: var(--space-4);
        right: var(--space-4);
        bottom: 1.4rem;
        grid-template-columns: 1fr;
        gap: 0.6rem;
        height: auto;
    }

    .progress-current {
        justify-self: center;
        padding-bottom: 0;
    }

    .indicators {
        align-items: start;
    }

    .indicator small {
        display: none;
    }

    .indicator-num {
        font-size: var(--text-xs);
    }

    .rail-track {
        top: 0.25rem;
    }
}

@media (max-width: 480px) {
    .indicator-num {
        display: none;
    }
}

@media (prefers-reduced-motion: reduce) {
    .rail-fill,
    .nav-menu,
    .nav-menu .nav-link,
    .nav-line {
        transition-duration: 1ms !important;
    }
}