/* =============================================================
   Science Habitat — Navigation Component (Complete)
   ============================================================= */

/* ─── Site Header Base Styles ─── */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: var(--sh-z-nav);
  background: rgba(10, 30, 58, 0.97);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255,255,255,0.08);
  height: var(--sh-nav-height);
}

.site-header__inner {
  max-width: var(--sh-container-max);
  margin: 0 auto;
  padding: 0 var(--sh-container-pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

/* ─── Logo / Branding ─── */
.site-branding {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}

.site-branding__logo svg {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
}

.site-branding__text {
  display: flex;
  flex-direction: column;
}

.site-branding__name {
  font-family: var(--sh-font-display);
  font-size: 1.15rem;
  color: var(--sh-white);
  line-height: 1.1;
  letter-spacing: 0.01em;
}

.site-branding__tagline {
  font-family: var(--sh-font-mono);
  font-size: 0.6rem;
  color: var(--sh-teal-light);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

/* ─── Primary Navigation Base ─── */
.primary-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.primary-nav ul {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.primary-nav li {
  position: relative;
  list-style: none;
}

.primary-nav a,
.primary-nav button {
  color: rgba(255,255,255,0.82);
  font-size: 0.88rem;
  font-weight: 500;
  font-family: var(--sh-font-body);
  text-decoration: none;
  padding: 8px 14px;
  border-radius: var(--sh-radius-sm);
  cursor: pointer;
  background: none;
  border: none;
  transition: color var(--sh-transition-fast), background var(--sh-transition-fast);
  display: flex;
  align-items: center;
  gap: 5px;
  white-space: nowrap;
}

.primary-nav a:hover,
.primary-nav button:hover {
  color: var(--sh-white);
  background: rgba(255,255,255,0.08);
}

.primary-nav a.is-active,
.primary-nav li.active > a {
  color: var(--sh-teal-light);
}

/* CTA button in nav */
.primary-nav .nav-cta a {
  background: var(--sh-orange) !important;
  color: var(--sh-white) !important;
  padding: 8px 20px;
  border-radius: var(--sh-radius-sm);
  font-weight: 600;
}

.primary-nav .nav-cta a:hover {
  background: var(--sh-orange-hover) !important;
}

/* ─── Dropdown Indicators ─── */
.primary-nav .menu-item--expanded > button::after,
.primary-nav .menu-item--has-children > a::after {
  content: '▾';
  font-size: 0.7rem;
  margin-left: 2px;
  transition: transform var(--sh-transition-fast);
  display: inline-block;
}

/* ─── Desktop Dropdown Styles (min-width: 769px) ─── */
@media (min-width: 769px) {
  /* Dropdown menu container - hidden by default */
  .primary-nav ul ul {
    display: none;
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    background: var(--sh-navy);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--sh-radius-md);
    min-width: 240px;
    box-shadow: 0 16px 40px rgba(0,0,0,0.3);
    flex-direction: column;
    overflow: hidden;
    z-index: var(--sh-z-dropdown);
  }

  /* Show dropdown when parent has dropdown-open class (set by JS) */
  .primary-nav .menu-item--expanded.dropdown-open > ul,
  .primary-nav .menu-item--has-children.dropdown-open > ul {
    display: flex;
  }

  /* Rotate arrow when dropdown is open */
  .primary-nav .menu-item--expanded.dropdown-open > button::after,
  .primary-nav .menu-item--has-children.dropdown-open > a::after {
    transform: rotate(180deg);
  }

  /* Submenu items styling */
  .primary-nav ul ul li {
    border-bottom: 1px solid rgba(255,255,255,0.06);
    width: 100%;
  }

  .primary-nav ul ul li:last-child {
    border-bottom: none;
  }

  .primary-nav ul ul a,
  .primary-nav ul ul button {
    color: rgba(255,255,255,0.75);
    font-size: 0.85rem;
    padding: 10px 18px;
    display: block;
    width: 100%;
    border-radius: 0;
    white-space: normal;
    text-align: left;
  }

  .primary-nav ul ul a:hover,
  .primary-nav ul ul button:hover {
    background: rgba(255,255,255,0.06);
    color: var(--sh-white);
  }
}


/* ─── Mobile Hamburger Button ─── */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
  background: none;
  border: none;
  z-index: calc(var(--sh-z-nav) + 1);
}

.nav-toggle__bar {
  width: 24px;
  height: 2px;
  background: var(--sh-white);
  border-radius: 2px;
  transition: transform var(--sh-transition-base), opacity var(--sh-transition-fast);
  display: block;
}

.nav-toggle.is-active .nav-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.is-active .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle.is-active .nav-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ─── Mobile Navigation Styles (max-width: 768px) ─── */
@media (max-width: 768px) {
  /* Show hamburger button */
  .nav-toggle {
    display: flex;
  }

  /* Mobile menu container */
  .primary-nav {
    display: none;
    position: fixed;
    top: var(--sh-nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--sh-navy);
    flex-direction: column;
    padding: 24px var(--sh-container-pad);
    overflow-y: auto;
    z-index: calc(var(--sh-z-nav) - 1);
    gap: 0;
    align-items: flex-start;
    justify-content: flex-start;
  }

  .primary-nav.is-open {
    display: flex;
  }

  /* Mobile menu list styles */
  .primary-nav ul {
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    width: 100%;
  }

  .primary-nav li {
    width: 100%;
  }

  .primary-nav a,
  .primary-nav button {
    width: 100%;
    padding: 14px 16px;
    border-radius: var(--sh-radius-sm);
    justify-content: space-between;
    border-bottom: 1px solid rgba(255,255,255,0.06);
    white-space: normal;
    text-align: left;
  }

  /* Dropdown indicator rotation on mobile */
  .primary-nav .menu-item--expanded > button::after,
  .primary-nav .menu-item--has-children > a::after {
    transition: transform var(--sh-transition-fast);
  }

  .primary-nav .menu-item--expanded.is-open > button::after,
  .primary-nav .menu-item--has-children.is-open > a::after {
    transform: rotate(180deg);
  }

  /* Mobile submenu styles */
  .primary-nav ul ul {
    display: none;
    position: static;
    box-shadow: none;
    border: none;
    background: rgba(255,255,255,0.04);
    border-radius: var(--sh-radius-sm);
    margin: 0 0 8px 16px;
    width: calc(100% - 16px);
    flex-direction: column;
  }

  .primary-nav ul ul.is-open {
    display: flex;
  }

  .primary-nav ul ul li {
    border-bottom: 1px solid rgba(255,255,255,0.04);
  }

  .primary-nav ul ul li:last-child {
    border-bottom: none;
  }

  .primary-nav ul ul a,
  .primary-nav ul ul button {
    padding: 12px 16px;
    border-bottom: none;
    font-size: 0.85rem;
  }

  /* Deep nested submenus on mobile */
  .primary-nav ul ul ul {
    margin-left: 16px;
    width: calc(100% - 16px);
  }

  /* Mobile CTA button */
  .primary-nav .nav-cta {
    margin-top: 16px;
    width: 100%;
  }

  .primary-nav .nav-cta a {
    justify-content: center;
    width: 100%;
  }

  /* Disable hover effects on mobile touch devices */
  .primary-nav a:active,
  .primary-nav button:active {
    background: rgba(255,255,255,0.12);
  }
}

/* ─── Tablet Styles (optional refinement) ─── */
@media (min-width: 769px) and (max-width: 1024px) {
  .primary-nav a,
  .primary-nav button {
    padding: 8px 10px;
    font-size: 0.85rem;
  }
  
  .primary-nav .nav-cta a {
    padding: 8px 16px;
  }
}

/* ─── Accessibility & Keyboard Navigation ─── */


/* Keyboard focus for dropdowns */
.primary-nav li:focus-within > ul {
  display: flex;
}

@media (max-width: 768px) {
  .primary-nav li:focus-within > ul {
    display: flex;
  }
}

/* ─── Reduced Motion Support ─── */
@media (prefers-reduced-motion: reduce) {
  .primary-nav a,
  .primary-nav button,
  .primary-nav ul ul,
  .nav-toggle__bar,
  .primary-nav .menu-item--expanded > button::after,
  .primary-nav .menu-item--has-children > a::after {
    transition: none;
  }
}

/* ─── High Contrast Mode Support ─── */
@media (prefers-contrast: high) {
  .site-header {
    background: var(--sh-navy);
    backdrop-filter: none;
    border-bottom-color: var(--sh-white);
  }
  
  .primary-nav a,
  .primary-nav button {
    border: 1px solid transparent;
  }
  
  .primary-nav a:hover,
  .primary-nav button:hover {
    border-color: var(--sh-white);
  }
  
  .primary-nav ul ul {
    border: 2px solid var(--sh-white);
  }
}

/* ─── Print Styles ─── */
@media print {
  .site-header {
    position: static;
    background: white;
    border-bottom: 1px solid #ccc;
  }
  
  .nav-toggle,
  .primary-nav button::after {
    display: none;
  }
  
  .primary-nav ul ul {
    display: flex;
    position: static;
    background: none;
    box-shadow: none;
    border: none;
    padding-left: 20px;
  }
  
  .primary-nav a,
  .primary-nav button {
    color: black;
    text-decoration: none;
  }
}