/* =====================================================================
   Volta Ad — Navigation (Header, Mega-menu, Mobile Drawer)
   ===================================================================== */

/* ── Site Header ────────────────────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  background: var(--color-bg-deep);
  border-bottom: 1px solid var(--color-border-dark);
  height: 64px;
  transition: background var(--transition-fast), backdrop-filter var(--transition-fast);
}
.site-header.is-scrolled {
  background: rgba(13,15,14,0.96);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: var(--space-5);
}

/* Logo */
.header-logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  flex-shrink: 0;
}
.header-logo img { height: 32px; width: auto; }
.header-logo__text {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--color-text-primary-dark);
  letter-spacing: -0.02em;
}
.header-logo__text .accent { color: var(--color-accent); }

/* Primary nav */
.primary-nav {
  display: none;
  align-items: center;
  gap: 0;
  flex: 1;
  justify-content: center;
}
@media (min-width: 900px) { .primary-nav { display: flex; } }

.nav-item {
  position: relative;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--font-medium);
  color: var(--color-text-primary-dark);
  text-decoration: none;
  /* reset native <button> styling (the Services trigger is a button) */
  background: transparent;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: color var(--transition-fast), background var(--transition-fast);
  white-space: nowrap;
  min-height: 44px;
}
.nav-link:hover { color: var(--color-accent); text-decoration: none; background: rgba(255,255,255,0.05); }
.nav-link.is-active {
  color: var(--color-accent);
  border-bottom: 2px solid var(--color-accent);
}
.nav-link svg { width: 14px; height: 14px; transition: transform var(--transition-fast); }
.nav-item--services > .nav-link[aria-expanded="true"] svg { transform: rotate(180deg); }

/* Header right */
.header-right {
  display: flex;
  align-items: center;
  gap: var(--space-5);
  flex-shrink: 0;
}
.header-phone {
  display: none;
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-secondary-dark);
  text-decoration: none;
  transition: color var(--transition-fast);
}
.header-phone:hover { color: var(--color-text-primary-dark); }
@media (min-width: 1280px) { .header-phone { display: block; } }

/* Hamburger */
.hamburger {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  color: var(--color-text-primary-dark);
}
@media (min-width: 900px) { .hamburger { display: none; } }
.hamburger svg { width: 24px; height: 24px; }

/* ── Mega-menu ──────────────────────────────────────────────────────── */
.mega-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  width: min(calc(100vw - 32px), 900px);
  background: var(--color-bg-section);
  border-top: 2px solid var(--color-accent);
  border-bottom: 1px solid var(--color-border-dark);
  border-radius: 0 0 var(--radius-xl) var(--radius-xl);
  box-shadow: var(--shadow-lg);
  z-index: var(--z-megamenu);
  display: none;
  opacity: 0;
  transform: translateX(-50%) translateY(-8px);
  transition: opacity 180ms ease-out, transform 180ms ease-out;
}
.mega-menu.is-open {
  display: grid;
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  .mega-menu { transition: none; }
}

.mega-menu-inner {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  padding: var(--space-8);
  gap: 0;
}

.mega-col {
  padding-right: var(--space-6);
}
.mega-col + .mega-col {
  border-left: 1px solid var(--color-border-dark);
  padding-left: var(--space-6);
  padding-right: var(--space-6);
}
.mega-col:last-child {
  padding-right: 0;
}

.mega-col__title {
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--color-text-secondary-dark);
  margin-bottom: var(--space-4);
  max-width: none;
}

.mega-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  margin: 0 calc(-1 * var(--space-4));
  text-decoration: none;
  border-radius: var(--radius-md);
  border-left: 2px solid transparent;
  transition: background var(--transition-fast), border-color var(--transition-fast);
}
.mega-item:hover {
  background: var(--color-surface-dark);
  border-left-color: var(--color-accent);
  text-decoration: none;
}
.mega-item__icon {
  width: 20px;
  height: 20px;
  color: var(--color-text-secondary-dark);
  flex-shrink: 0;
  margin-top: 2px;
  transition: color var(--transition-fast);
}
.mega-item:hover .mega-item__icon { color: var(--color-accent); }
.mega-item__text {}
.mega-item__name {
  display: block;
  font-size: var(--text-base);
  font-weight: var(--font-medium);
  color: var(--color-text-primary-dark);
  line-height: 1.3;
}
.mega-item__desc {
  display: block;
  font-size: var(--text-sm);
  color: var(--color-text-secondary-dark);
  margin-top: 2px;
  max-width: none;
}

/* Mega rail (featured) */
.mega-rail {
  background: var(--color-surface-dark);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  border-left: 4px solid var(--color-accent);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}
.mega-rail__overline {
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--color-accent);
  max-width: none;
}
.mega-rail__heading {
  font-family: var(--font-display);
  font-size: var(--text-md);
  font-weight: var(--font-bold);
  color: var(--color-text-primary-dark);
  line-height: var(--leading-snug);
  max-width: none;
}
.mega-rail__body {
  font-size: var(--text-sm);
  color: var(--color-text-secondary-dark);
  line-height: var(--leading-normal);
  max-width: none;
}
.mega-rail__link {
  font-size: var(--text-sm);
  color: var(--color-accent);
  font-weight: var(--font-medium);
}
.mega-rail__link:hover { text-decoration: underline; }
.mega-rail__sep { border: none; border-top: 1px solid var(--color-border-dark); margin: var(--space-2) 0; }

/* ── Mobile Drawer ──────────────────────────────────────────────────── */
.drawer-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  z-index: calc(var(--z-drawer) - 1);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-slow);
}
.drawer-overlay.is-open { opacity: 1; pointer-events: auto; }

.site-drawer {
  position: fixed;
  top: 0;
  right: 0;
  height: 100%;
  width: min(100vw, 380px);
  background: var(--color-bg-deep);
  z-index: var(--z-drawer);
  box-shadow: var(--shadow-xl);
  overflow-y: auto;
  transform: translateX(100%);
  transition: transform var(--transition-slow);
  display: flex;
  flex-direction: column;
}
.site-drawer.is-open { transform: translateX(0); }
@media (prefers-reduced-motion: reduce) {
  .site-drawer { transition: none; }
  .drawer-overlay { transition: none; }
}

.drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-6);
  border-bottom: 1px solid var(--color-border-dark);
  height: 64px;
  flex-shrink: 0;
}

.drawer-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text-primary-dark);
  border-radius: var(--radius-md);
}
.drawer-close svg { width: 24px; height: 24px; }

.drawer-nav {
  flex: 1;
  padding: var(--space-4) 0;
}

.drawer-nav-item {
  border-bottom: 1px solid var(--color-border-dark);
}

.drawer-nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-6);
  font-size: var(--text-md);
  font-weight: var(--font-medium);
  color: var(--color-text-primary-dark);
  text-decoration: none;
  min-height: 48px;
  transition: color var(--transition-fast);
}
.drawer-nav-link:hover { color: var(--color-accent); text-decoration: none; }
.drawer-nav-link svg { width: 16px; height: 16px; transition: transform var(--transition-fast); }
.drawer-nav-link[aria-expanded="true"] svg { transform: rotate(180deg); }

/* Services accordion inside drawer */
.drawer-services {
  background: var(--color-bg-section);
  display: none;
}
.drawer-services.is-open { display: block; }
.drawer-service-link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-8);
  font-size: var(--text-base);
  color: var(--color-text-secondary-dark);
  text-decoration: none;
  border-bottom: 1px solid rgba(255,255,255,0.04);
  min-height: 44px;
  transition: color var(--transition-fast);
}
.drawer-service-link:hover { color: var(--color-text-primary-dark); text-decoration: none; }
.drawer-service-link svg { width: 16px; height: 16px; color: var(--color-accent); flex-shrink: 0; }

.drawer-footer {
  padding: var(--space-6);
  border-top: 1px solid var(--color-border-dark);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  flex-shrink: 0;
}
.drawer-phone {
  font-size: var(--text-sm);
  color: var(--color-text-secondary-dark);
  text-decoration: none;
  text-align: center;
}