/* ══════════════════════════════════════════
   Site Navigation – Desktop + Burger Menu
   ══════════════════════════════════════════ */

.site-nav {
    position: sticky;
    top: 0;
    z-index: 200;
    padding: 1.2rem 0;
    background-color: rgba(252, 252, 252, 0.95);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--line-color);
    transition: box-shadow 0.3s ease;
}

.site-nav.scrolled {
    box-shadow: 0 1px 12px rgba(0, 0, 0, 0.05);
}

.site-nav .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

/* Logo */
.nav-logo {
    font-family: var(--font-heading);
    font-size: 1.15rem;
    letter-spacing: -0.01em;
    color: var(--text-color);
    text-decoration: none;
    flex-shrink: 0;
    transition: opacity 0.2s ease;
    z-index: 200;
    position: relative;
}

.nav-logo:hover {
    opacity: 0.65;
}

/* Desktop Links */
.nav-links {
    display: flex;
    align-items: center;
    gap: 2.5rem;
}

.nav-links a {
    font-size: 0.8rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--accent-color);
    text-decoration: none;
    padding-bottom: 2px;
    border-bottom: 1px solid transparent;
    transition: color 0.2s ease, border-color 0.2s ease;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-color);
    border-bottom-color: var(--text-color);
    opacity: 1;
}

/* ── Burger Button ── */
.nav-burger {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
    position: relative;
    z-index: 200;
    flex-shrink: 0;
}

.nav-burger span {
    display: block;
    width: 22px;
    height: 1.5px;
    background-color: var(--text-color);
    border-radius: 2px;
    transition: transform 0.35s cubic-bezier(0.23, 1, 0.32, 1),
                opacity 0.25s ease,
                width 0.3s ease;
    transform-origin: center;
}

/* Burger → X animation */
.nav-burger[aria-expanded="true"] span:nth-child(1) {
    transform: translateY(6.5px) rotate(45deg);
}
.nav-burger[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
    width: 0;
}
.nav-burger[aria-expanded="true"] span:nth-child(3) {
    transform: translateY(-6.5px) rotate(-45deg);
}

/* ── Mobile Overlay ── */
.nav-overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 190;
    background-color: rgba(252, 252, 252, 0.98);
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
    padding: 5rem var(--spacing-unit) 4rem;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.nav-overlay.open {
    display: flex;
    opacity: 1;
}

.nav-overlay a {
    font-family: var(--font-heading);
    font-size: clamp(1.8rem, 6vw, 2.8rem);
    font-weight: 400;
    color: var(--text-color);
    text-decoration: none;
    line-height: 1.15;
    margin-bottom: 0.6rem;
    opacity: 0;
    transform: translateX(-16px);
    transition: color 0.2s ease;

    /* Stagger set via JS */
}

.nav-overlay.open a {
    animation: navItemIn 0.4s cubic-bezier(0.23, 1, 0.32, 1) forwards;
}

.nav-overlay a:nth-child(1) { animation-delay: 0.05s; }
.nav-overlay a:nth-child(2) { animation-delay: 0.12s; }
.nav-overlay a:nth-child(3) { animation-delay: 0.19s; }
.nav-overlay a:nth-child(4) { animation-delay: 0.26s; }
.nav-overlay a:nth-child(5) { animation-delay: 0.33s; }
.nav-overlay a:nth-child(6) { animation-delay: 0.40s; }

.nav-overlay a:hover {
    color: var(--accent-color);
}

.nav-overlay a.active {
    color: var(--accent-color);
}

.nav-overlay-divider {
    width: 40px;
    height: 1px;
    background-color: var(--line-color);
    margin: 1.5rem 0;
    flex-shrink: 0;
    opacity: 0;
    animation: navItemIn 0.4s cubic-bezier(0.23, 1, 0.32, 1) 0.3s forwards;
}

@keyframes navItemIn {
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Body scroll lock when menu open */
body.nav-open {
    overflow: hidden;
}

/* ── Responsive ── */
@media (max-width: 767px) {
    .nav-links {
        display: none; /* replaced by overlay */
    }

    .nav-burger {
        display: flex;
    }
}

@media (min-width: 768px) {
    .nav-overlay {
        display: none !important;
    }
}