/* ── Header ── */
#header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-h);
  display: flex;
  align-items: center;
  padding: 0 var(--gutter);
  transition: background 0.5s var(--ease-io), border-color 0.5s var(--ease-io);
  border-bottom: 1px solid transparent;
}

#header.scrolled {
  background: rgba(10, 9, 8, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom-color: rgba(255,255,255,0.08);
}

.header-inner {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-family: var(--font-ui);
  font-weight: 900;
  font-size: 18px;
  letter-spacing: 0.06em;
  color: var(--white);
  text-transform: uppercase;
}

.nav {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav a {
  font-family: var(--font-ui);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--stone);
  transition: color 0.3s var(--ease-out);
  position: relative;
}

.nav a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--white);
  transition: width 0.3s var(--ease-out);
}

.nav a:hover { color: var(--white); }
.nav a:hover::after { width: 100%; }

/* Hamburger */
#hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  cursor: pointer;
}

#hamburger span {
  display: block;
  width: 22px;
  height: 1px;
  background: var(--white);
  transition: transform 0.4s var(--ease-out), opacity 0.3s var(--ease-out);
  transform-origin: center;
}

#hamburger.open span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
#hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
#hamburger.open span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* Mobile nav overlay */
#mobile-nav {
  position: fixed;
  inset: 0;
  background: var(--black);
  z-index: 999;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 40px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s var(--ease-out);
}

#mobile-nav.open {
  opacity: 1;
  pointer-events: all;
}

#mobile-nav a {
  font-family: var(--font-display);
  font-size: clamp(36px, 8vw, 64px);
  font-style: italic;
  font-weight: 300;
  color: var(--white);
  transition: color 0.2s var(--ease-out);
}

#mobile-nav a:hover { color: var(--stone); }