/* ==========================================================================
   Header — Fixed navigation with hover dropdown menus & mobile hamburger
   ========================================================================== */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: var(--z-sticky);
  background: var(--color-white);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base);
}

.site-header.scrolled {
  box-shadow: var(--shadow-md);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
  height: 70px;
}

/* ── Logo / Brand ── */
.header-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  flex-shrink: 0;
}

.header-brand:hover {
  text-decoration: none;
}

.header-logo-text {
  font-family: var(--font-heading);
  font-weight: var(--fw-extrabold);
  font-size: var(--fs-xl);
  color: var(--color-primary);
  line-height: 1;
}

.header-logo-text span {
  display: block;
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  color: var(--color-text-muted);
  letter-spacing: 0.5px;
}

/* ── Desktop Navigation ── */
.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.header-nav > a {
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-heading);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-dark-grey);
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), background var(--transition-fast);
  white-space: nowrap;
}

.header-nav > a:hover {
  color: var(--color-primary);
  background: rgba(11, 61, 107, 0.05);
  text-decoration: none;
}

.header-nav > a.active {
  color: var(--color-primary);
  background: rgba(11, 61, 107, 0.08);
  font-weight: var(--fw-semibold);
}

/* ── Dropdown container ── */
.nav-dropdown {
  position: relative;
}

.nav-dropdown-label {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-heading);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-dark-grey);
  border-radius: var(--radius-md);
  cursor: default;
  transition: color var(--transition-fast), background var(--transition-fast);
  white-space: nowrap;
  user-select: none;
}

.nav-dropdown:hover > .nav-dropdown-label,
.nav-dropdown-label.parent-active:hover {
  color: var(--color-primary);
  background: rgba(11, 61, 107, 0.05);
}

.nav-dropdown-label.parent-active {
  color: var(--color-primary);
  background: rgba(11, 61, 107, 0.08);
  font-weight: var(--fw-semibold);
}

.nav-dropdown-label .chevron {
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

.nav-dropdown:hover > .nav-dropdown-label .chevron {
  transform: rotate(180deg);
}

/* ── Dropdown menu (desktop — pure CSS hover) ── */
.nav-dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 190px;
  padding: var(--space-2) 0;
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(4px);
  transition: opacity var(--transition-fast), transform var(--transition-fast), visibility var(--transition-fast);
  z-index: calc(var(--z-sticky) + 10);
}

/* Show on hover — the entire .nav-dropdown area including menu */
.nav-dropdown:hover > .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-dropdown-menu a {
  display: block;
  padding: var(--space-2) var(--space-4);
  font-family: var(--font-heading);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-dark-grey);
  text-decoration: none;
  transition: color var(--transition-fast), background var(--transition-fast);
  white-space: nowrap;
}

.nav-dropdown-menu a:hover {
  color: var(--color-primary);
  background: rgba(11, 61, 107, 0.05);
  text-decoration: none;
}

.nav-dropdown-menu a.active {
  color: var(--color-primary);
  font-weight: var(--fw-semibold);
  background: rgba(11, 61, 107, 0.08);
}

/* ── Hamburger button ── */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  padding: 6px;
  cursor: pointer;
  z-index: calc(var(--z-overlay) + 1);
}

.hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-primary);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-fast);
}

/* Hamburger → X animation */
.hamburger.is-open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.hamburger.is-open span:nth-child(2) {
  opacity: 0;
}
.hamburger.is-open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ── Small screen header adjustments ── */
@media (max-width: 480px) {
  .header-inner {
    padding: 0 var(--space-4);
  }
  .header-logo-text {
    font-size: var(--fs-lg);
  }
  .header-logo-text span {
    font-size: 0.625rem;
  }
}

/* ── Mobile nav ── */
@media (max-width: 1024px) {
  .hamburger {
    display: flex;
  }

  .header-nav {
    position: fixed;
    top: 0;
    right: 0;
    width: 280px;
    height: 100vh;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: 80px var(--space-6) var(--space-8);
    background: var(--color-white);
    box-shadow: var(--shadow-xl);
    transform: translateX(100%);
    transition: transform var(--transition-base);
    overflow-y: auto;
    z-index: calc(var(--z-overlay) + 1);
  }

  .header-nav.is-open {
    transform: translateX(0);
  }

  .header-nav > a {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-size: var(--fs-base);
    border-radius: var(--radius-md);
  }

  /* Dropdown — full width in mobile */
  .nav-dropdown {
    width: 100%;
  }

  .nav-dropdown-label {
    width: 100%;
    justify-content: space-between;
    padding: var(--space-3) var(--space-4);
    font-size: var(--fs-base);
    border-radius: var(--radius-md);
    cursor: pointer;
  }

  /* Disable CSS hover on mobile — use JS .is-open instead */
  .nav-dropdown:hover > .nav-dropdown-menu {
    opacity: 0;
    visibility: hidden;
    transform: translateY(4px);
  }

  .nav-dropdown:hover > .nav-dropdown-label .chevron {
    transform: none;
  }

  /* Dropdown menu — accordion style in mobile */
  .nav-dropdown-menu {
    position: static;
    min-width: 0;
    padding: 0;
    background: transparent;
    border-radius: 0;
    box-shadow: none;
    opacity: 1;
    visibility: visible;
    transform: none;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
  }

  /* JS toggles .is-open on mobile tap */
  .nav-dropdown.is-open > .nav-dropdown-menu {
    max-height: 300px;
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav-dropdown.is-open > .nav-dropdown-label .chevron {
    transform: rotate(180deg);
  }

  .nav-dropdown-menu a {
    padding: var(--space-2) var(--space-4) var(--space-2) var(--space-8);
    font-size: var(--fs-sm);
    color: var(--color-text-muted);
  }

  .nav-dropdown-menu a:hover {
    color: var(--color-primary);
  }

  .nav-dropdown-menu a.active {
    color: var(--color-primary);
    font-weight: var(--fw-semibold);
  }

  /* Overlay behind mobile menu */
  .nav-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: var(--z-overlay);
  }
  .nav-overlay.is-visible {
    display: block;
  }
}