/* ==========================================================================
   EDURICH INTERNATIONAL CAMPUS - GLOBAL HEADER & TOP UTILITY BAR
   Matches UI references: Picture1.jpg, Picture3.jpg, Picture4.jpg, Picture5.jpg
   Features:
   - Fixed top position on scroll
   - Smooth size reduction (shrink effect) on scroll down
   - Glassmorphic frosted backdrop with sleek multi-layer elevation
   - Proportional brand logo scaling
   - Zero-layout-shift flow spacer
   ========================================================================== */

/* --------------------------------------------------------------------------
   0. Fixed Header Shell & Flow Spacer
   -------------------------------------------------------------------------- */
.header-fixed-shell {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  width: 100%;
  z-index: 1000;
  margin: 0;
  padding: 0;
  border: none;
  background: transparent;
  transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.header-flow-spacer {
  height: calc(var(--header-height-top, 38px) + var(--header-height-main, 76px));
  width: 100%;
  pointer-events: none;
}

/* --------------------------------------------------------------------------
   1. Top Utility Bar (Dark Slate)
   -------------------------------------------------------------------------- */
.top-utility-bar {
  background-color: var(--color-dark-nav);
  color: var(--color-text-light);
  font-size: var(--font-size-xs);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  position: relative;
  z-index: 101;
  max-height: 48px;
  height: auto;
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  transition: max-height 0.28s cubic-bezier(0.16, 1, 0.3, 1),
              opacity 0.22s ease,
              visibility 0.28s ease,
              transform 0.28s cubic-bezier(0.16, 1, 0.3, 1);
  overflow: hidden;
}

.header-scrolled .top-utility-bar {
  max-height: 0 !important;
  height: 0 !important;
  min-height: 0 !important;
  padding-top: 0 !important;
  padding-bottom: 0 !important;
  margin-top: 0 !important;
  margin-bottom: 0 !important;
  border-bottom-width: 0 !important;
  border-bottom-color: transparent !important;
  border: none !important;
  opacity: 0 !important;
  visibility: hidden !important;
  transform: translateY(-100%) !important;
  pointer-events: none !important;
  overflow: hidden !important;
}

.top-utility-bar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-height-top);
  padding-top: 4px;
  padding-bottom: 4px;
  transition: min-height 0.28s cubic-bezier(0.16, 1, 0.3, 1),
              padding 0.28s cubic-bezier(0.16, 1, 0.3, 1);
}

.header-scrolled .top-utility-bar .container {
  min-height: 0 !important;
  height: 0 !important;
  padding-top: 0 !important;
  padding-bottom: 0 !important;
  overflow: hidden !important;
}

.header-scrolled .main-header {
  margin-top: 0 !important;
}

.top-bar-left {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.top-bar-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: #CBD5E1;
  font-weight: var(--font-weight-medium);
  transition: color var(--transition-fast);
}

.top-bar-link:hover {
  color: var(--color-text-white);
}

.top-bar-link svg {
  width: 13px;
  height: 13px;
  stroke-width: 2.2;
}

.top-bar-right {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.top-bar-action {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  color: #E2E8F0;
  font-weight: var(--font-weight-medium);
  transition: color var(--transition-fast);
}

.top-bar-action:hover {
  color: var(--color-text-white);
}

.top-bar-action svg {
  width: 14px;
  height: 14px;
}

.top-bar-btn {
  background-color: var(--color-primary);
  color: var(--color-text-white) !important;
  font-weight: var(--font-weight-semibold);
  padding: 4px 14px;
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast);
  margin-left: var(--spacing-xs);
}

.top-bar-btn:hover {
  background-color: var(--color-primary-hover);
}

/* --------------------------------------------------------------------------
   2. Main Navigation Bar (White, Sticky/Fixed, Shrinking)
   -------------------------------------------------------------------------- */
.main-header {
  background-color: var(--color-bg-card);
  border-bottom: 1px solid var(--color-border);
  position: relative;
  z-index: 100;
  box-shadow: var(--shadow-xs);
  transition: background-color 0.3s ease,
              backdrop-filter 0.3s ease,
              -webkit-backdrop-filter 0.3s ease,
              box-shadow 0.35s cubic-bezier(0.16, 1, 0.3, 1),
              border-color 0.3s ease;
}

.main-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height-main); /* 76px */
  transition: height 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ── SCROLLED COMPACT REDUCED STATE ────────────────────────────────────── */
.main-header.scrolled,
.header-scrolled .main-header {
  background-color: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 4px 20px -2px rgba(11, 21, 48, 0.08), 0 2px 6px -1px rgba(11, 21, 48, 0.04);
  border-bottom-color: rgba(226, 232, 240, 0.85);
}

.main-header.scrolled .container,
.header-scrolled .main-header .container {
  height: 56px; /* Smoothly reduced from 76px */
}

/* Brand Logo */
.brand-logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  transition: gap 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.logo-main {
  font-family: var(--font-family-heading);
  font-size: 2.05rem;
  font-weight: var(--font-weight-extrabold);
  color: var(--color-primary);
  letter-spacing: -0.035em;
  line-height: 1;
  -webkit-text-stroke: 0.45px var(--color-primary);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  transition: font-size 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.logo-divider {
  width: 2px;
  height: 34px;
  background-color: #CBD5E1;
  border-radius: 1px;
  transition: height 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.logo-sub {
  display: flex;
  flex-direction: column;
  font-size: 0.82rem;
  font-weight: var(--font-weight-bold);
  text-transform: uppercase;
  letter-spacing: 0.055em;
  color: #1E293B;
  line-height: 1.15;
  transition: font-size 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Scrolled Logo Reductions */
.main-header.scrolled .brand-logo,
.header-scrolled .main-header .brand-logo {
  gap: 10px;
}

.main-header.scrolled .logo-main,
.header-scrolled .main-header .logo-main {
  font-size: 1.62rem;
}

.main-header.scrolled .logo-divider,
.header-scrolled .main-header .logo-divider {
  height: 24px;
}

.main-header.scrolled .logo-sub,
.header-scrolled .main-header .logo-sub {
  font-size: 0.72rem;
  letter-spacing: 0.045em;
}

/* Desktop Nav Items */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 28px;
  margin: 0;
  padding: 0;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 10px 0;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-main);
  transition: color var(--transition-fast),
              padding 0.35s cubic-bezier(0.16, 1, 0.3, 1),
              font-size 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
}

.main-header.scrolled .nav-link,
.header-scrolled .main-header .nav-link {
  padding: 6px 0;
  font-size: 0.82rem;
}

.nav-link:hover {
  color: var(--color-primary);
}

.nav-link.active {
  color: var(--color-primary);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 100%;
  height: 3px;
  background-color: var(--color-primary);
  border-radius: var(--radius-pill);
}

.main-header.scrolled .nav-link.active::after,
.header-scrolled .main-header .nav-link.active::after {
  bottom: -2px;
}

.nav-chevron {
  width: 12px;
  height: 12px;
  stroke-width: 2.5;
  transition: transform var(--transition-fast);
}

.nav-item:hover .nav-chevron {
  transform: translateY(1px);
}

/* Dropdown Menu */
.nav-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 8px 0;
  min-width: 240px;
  box-shadow: 0 12px 30px -4px rgba(15, 23, 42, 0.12), 0 4px 8px -2px rgba(15, 23, 42, 0.04);
  opacity: 0;
  visibility: hidden;
  transform: translateY(6px);
  transition: opacity 0.2s cubic-bezier(0.16, 1, 0.3, 1), transform 0.2s cubic-bezier(0.16, 1, 0.3, 1), visibility 0.2s;
  z-index: 110;
  pointer-events: none;
}

.nav-item:hover .nav-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

.dropdown-link {
  display: block;
  padding: 8px 18px;
  font-size: var(--font-size-sm);
  color: var(--color-text-main);
  font-weight: var(--font-weight-medium);
  transition: all var(--transition-fast);
}

.dropdown-link:hover {
  background-color: var(--color-primary-light);
  color: var(--color-primary);
  padding-left: 22px;
}

/* Header Right Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.search-trigger-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-pill);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-main);
  background-color: transparent;
  transition: all var(--transition-fast),
              width 0.35s cubic-bezier(0.16, 1, 0.3, 1),
              height 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.main-header.scrolled .search-trigger-btn,
.header-scrolled .main-header .search-trigger-btn {
  width: 34px;
  height: 34px;
}

.search-trigger-btn:hover {
  background-color: var(--color-bg-alt);
  color: var(--color-primary);
}

.search-trigger-btn svg {
  width: 18px;
  height: 18px;
  stroke-width: 2.2;
}

/* Mobile Hamburger Toggle */
.mobile-toggle-btn {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  color: var(--color-text-main);
  border-radius: var(--radius-sm);
  transition: width 0.35s cubic-bezier(0.16, 1, 0.3, 1),
              height 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.main-header.scrolled .mobile-toggle-btn,
.header-scrolled .main-header .mobile-toggle-btn {
  width: 34px;
  height: 34px;
}

.mobile-toggle-btn svg {
  width: 24px;
  height: 24px;
}

/* --------------------------------------------------------------------------
   3. Mobile Navigation Drawer
   -------------------------------------------------------------------------- */
.mobile-drawer-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background-color: rgba(11, 19, 37, 0.6);
  backdrop-filter: blur(4px);
  z-index: 1050;
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.mobile-drawer-overlay.open {
  display: block;
  opacity: 1;
}

.mobile-drawer {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 320px;
  max-width: 85vw;
  background-color: var(--color-bg-card);
  z-index: 1051;
  transform: translateX(100%);
  transition: transform var(--transition-smooth);
  display: flex;
  flex-direction: column;
  box-shadow: -4px 0 20px rgba(0, 0, 0, 0.15);
}

.mobile-drawer.open {
  transform: translateX(0);
}

.mobile-drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--color-border);
}

.mobile-close-btn {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-main);
  border-radius: var(--radius-sm);
}

.mobile-drawer-body {
  padding: var(--spacing-lg);
  overflow-y: auto;
  flex-grow: 1;
}

.mobile-nav-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.mobile-nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 14px;
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-main);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.mobile-nav-link:hover,
.mobile-nav-link.active {
  background-color: var(--color-primary-light);
  color: var(--color-primary);
}

.mobile-nav-link:active {
  transform: scale(0.985);
  background-color: var(--color-primary-muted);
}

.mobile-sub-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 4px 0 8px 14px;
  border-left: 2px solid rgba(196, 0, 98, 0.2);
  margin: 2px 0 8px 14px;
}

.mobile-sub-link {
  display: block;
  padding: 7px 12px;
  font-size: 0.88rem;
  color: var(--color-text-muted);
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: all var(--transition-fast);
}

.mobile-sub-link:hover,
.mobile-sub-link:active {
  color: var(--color-primary);
  background-color: var(--color-primary-light);
}

.mobile-drawer-footer {
  padding: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
  background-color: var(--color-bg-body);
}

/* --------------------------------------------------------------------------
   Responsive Media Queries
   -------------------------------------------------------------------------- */
@media (max-width: 992px) {
  /* Remove top utility bar on mobile view */
  .top-utility-bar {
    display: none !important;
  }

  .header-flow-spacer {
    height: 72px;
  }

  .main-header {
    border-bottom: 1px solid rgba(15, 23, 42, 0.08);
    box-shadow: 0 1px 3px rgba(11, 19, 37, 0.04), 0 4px 12px rgba(11, 19, 37, 0.02);
  }

  .nav-menu {
    display: none;
  }

  .header-actions {
    display: flex;
    align-items: center;
    gap: 4px;
  }

  .search-trigger-btn,
  .mobile-toggle-btn {
    width: 44px;
    height: 44px;
    min-width: 44px;
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
  }

  .mobile-toggle-btn {
    display: flex;
  }
}

@media (max-width: 576px) {
  .header-flow-spacer {
    height: 64px;
  }

  .main-header .container {
    height: 64px;
    padding-left: 16px;
    padding-right: 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
  }

  .main-header.scrolled .container,
  .header-scrolled .main-header .container {
    height: 56px;
  }

  .brand-logo {
    gap: 10px;
    display: inline-flex;
    align-items: center;
  }

  .logo-main {
    font-size: 1.72rem;
    line-height: 1;
  }

  .main-header.scrolled .logo-main,
  .header-scrolled .main-header .logo-main {
    font-size: 1.45rem;
  }

  .logo-divider {
    height: 26px;
  }

  .main-header.scrolled .logo-divider,
  .header-scrolled .main-header .logo-divider {
    height: 20px;
  }

  .logo-sub {
    font-size: 0.70rem;
    line-height: 1.15;
    letter-spacing: 0.04em;
  }

  .main-header.scrolled .logo-sub,
  .header-scrolled .main-header .logo-sub {
    font-size: 0.64rem;
  }
}

@media (max-width: 375px) {
  .main-header .container {
    padding-left: 12px;
    padding-right: 12px;
  }

  .brand-logo {
    gap: 8px;
  }

  .logo-main {
    font-size: 1.55rem;
  }

  .logo-divider {
    height: 22px;
  }

  .logo-sub {
    font-size: 0.64rem;
  }

  .header-actions {
    gap: 2px;
  }

  .search-trigger-btn,
  .mobile-toggle-btn {
    width: 40px;
    height: 40px;
    min-width: 40px;
    min-height: 40px;
  }
}