/* ============================================
   OSBORN ASSOCIATES - Navigation
   ============================================ */

.header { position: fixed; top: 0; left: 0; right: 0; z-index: 10000; transition: transform var(--dur-base) var(--ease), background-color var(--dur-base) var(--ease), backdrop-filter var(--dur-base) var(--ease); }
.header--scrolled { background-color: rgba(30,32,37,0.88); backdrop-filter: blur(20px) saturate(1.2); -webkit-backdrop-filter: blur(20px) saturate(1.2); }
.header--hidden { transform: translateY(-100%); }

.nav { max-width: var(--max-width); margin: 0 auto; padding: 0 var(--section-px); height: 80px; display: flex; align-items: center; justify-content: space-between; }
.nav__logo { flex-shrink: 0; z-index: 1001; }
.nav__logo img { height: 56px; width: auto; }

.nav__links { display: flex; align-items: center; gap: clamp(28px, 3vw, 48px); }
.nav__link { font-family: var(--font-sans); font-size: 0.6875rem; font-weight: 400; letter-spacing: 0.1em; text-transform: uppercase; color: var(--warm-stone); padding: 8px 0; position: relative; transition: color var(--dur-base) var(--ease); }
.nav__link:hover, .nav__link--active { color: var(--warm-off-white); }

.nav__dropdown { position: relative; }
.nav__dropdown-trigger { display: flex; align-items: center; gap: 6px; cursor: pointer; }
.nav__dropdown-arrow { width: 8px; height: 8px; border-right: 1px solid currentColor; border-bottom: 1px solid currentColor; transform: rotate(45deg) translateY(-2px); opacity: 0.4; transition: transform var(--dur-base) var(--ease), opacity var(--dur-base) var(--ease); }
.nav__dropdown:hover .nav__dropdown-arrow { transform: rotate(-135deg) translateY(-2px); opacity: 0.7; }
.nav__dropdown-panel { position: absolute; top: 100%; left: -16px; padding-top: 12px; opacity: 0; visibility: hidden; transform: translateY(-4px); transition: all var(--dur-base) var(--ease); }
.nav__dropdown:hover .nav__dropdown-panel { opacity: 1; visibility: visible; transform: translateY(0); }
.nav__dropdown-inner { background: rgba(37,40,48,0.97); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px); border: 1px solid rgba(122,154,181,0.08); border-radius: var(--radius-sm); padding: 8px 0; min-width: 220px; }
.nav__dropdown-link { display: block; font-family: var(--font-sans); font-size: 0.6875rem; font-weight: 400; letter-spacing: 0.06em; text-transform: uppercase; color: var(--warm-stone); padding: 10px 20px; border-left: 2px solid transparent; transition: all var(--dur-fast) var(--ease); }
.nav__dropdown-link:hover { color: var(--warm-off-white); background: rgba(122,154,181,0.06); border-left-color: var(--muted-blue); }

/* CTA */
.nav__cta { margin-left: clamp(16px, 2vw, 32px); }
.nav__cta .btn--nav { color: var(--warm-off-white); background-color: transparent; border-color: rgba(244,241,236,0.35); font-weight: 400; padding: 10px 24px; font-size: 0.625rem; }
.nav__cta .btn--nav:hover { background-color: var(--warm-off-white); border-color: var(--warm-off-white); color: var(--charcoal-deep); }

/* Hamburger */
.nav__hamburger { display: none; flex-direction: column; justify-content: center; gap: 6px; width: 24px; height: 24px; position: relative; cursor: pointer; -webkit-tap-highlight-color: transparent; }
.nav__hamburger span { display: block; width: 24px; height: 1.5px; background-color: var(--warm-off-white); transition: all var(--dur-base) var(--ease); }
.nav__hamburger--open span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.nav__hamburger--open span:nth-child(2) { opacity: 0; }
.nav__hamburger--open span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

/* Mobile overlay - solid backdrop at any scroll position */
.nav__mobile {
  position: fixed; inset: 0; z-index: 9999;
  background: var(--charcoal-deep);
  display: flex; flex-direction: column; justify-content: center;
  padding: 100px var(--section-px) 60px;
  transform: translateY(-100%);
  visibility: hidden;
  transition: transform var(--dur-slow) var(--ease), visibility 0s linear 0.5s;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}
.nav__mobile::before {
  content: ''; position: absolute; inset: 0;
  opacity: var(--grid-opacity-dark); pointer-events: none;
  background-image: linear-gradient(rgba(122,154,181,0.4) 1px, transparent 1px), linear-gradient(90deg, rgba(122,154,181,0.4) 1px, transparent 1px);
  background-size: 80px 80px;
}
.nav__mobile--open {
  transform: translateY(0);
  visibility: visible;
  transition: transform var(--dur-slow) var(--ease), visibility 0s linear 0s;
}

/* Direct links */
.nav__mobile-link {
  font-family: var(--font-serif); font-size: clamp(1.6rem, 4.5vw, 2.2rem); font-weight: 400;
  color: var(--warm-off-white); padding: 14px 0; display: block; position: relative; z-index: 1;
  opacity: 0.85; transition: opacity var(--dur-base) var(--ease);
}
.nav__mobile-link:hover { opacity: 1; }

/* Accordion groups */
.nav__mobile-group { position: relative; z-index: 1; }

.nav__mobile-accordion-trigger {
  font-family: var(--font-serif); font-size: clamp(1.6rem, 4.5vw, 2.2rem); font-weight: 400;
  color: var(--warm-off-white); padding: 14px 0; display: flex; align-items: center;
  justify-content: space-between; width: 100%; opacity: 0.85;
  transition: opacity var(--dur-base) var(--ease); cursor: pointer;
  background: none; border: none; text-align: left;
  -webkit-tap-highlight-color: transparent;
}
.nav__mobile-accordion-trigger:hover { opacity: 1; }

/* Plus/minus indicator */
.nav__mobile-accordion-icon {
  font-family: var(--font-sans); font-size: 1.2rem; font-weight: 300;
  color: var(--muted-blue); opacity: 0.4; transition: opacity var(--dur-base) var(--ease);
  flex-shrink: 0; margin-left: 16px;
}
.nav__mobile-group--open .nav__mobile-accordion-icon { opacity: 0.7; }

/* Submenu - hidden by default */
.nav__mobile-sub {
  max-height: 0; overflow: hidden;
  transition: max-height var(--dur-slow) var(--ease);
  padding-left: 20px;
}
.nav__mobile-group--open .nav__mobile-sub { max-height: 400px; }

.nav__mobile-sub a {
  font-family: var(--font-sans); font-size: 0.75rem; font-weight: 400;
  letter-spacing: 0.08em; text-transform: uppercase; color: var(--warm-stone);
  padding: 8px 0; display: block; border-left: 1px solid rgba(122,154,181,0.1); padding-left: 16px;
  transition: all var(--dur-fast) var(--ease);
}
.nav__mobile-sub a:hover { color: var(--warm-off-white); border-left-color: var(--muted-blue); }

@media (max-width: 960px) {
  .nav__links, .nav__cta { display: none; }
  .nav__hamburger { display: flex; }
}

/* Mobile menu contact footer */
.nav__mobile-contact {
  margin-top: auto; padding-top: 32px; position: relative; z-index: 1;
  border-top: 1px solid rgba(122,154,181,0.08);
}
.nav__mobile-contact a {
  font-family: var(--font-sans); font-size: 0.6875rem; font-weight: 400;
  letter-spacing: 0.06em; color: var(--warm-stone); opacity: 0.5;
  display: block; padding: 6px 0; transition: opacity var(--dur-base) var(--ease);
}
.nav__mobile-contact a:hover { opacity: 0.8; }