@media (min-width: 1024px) {
  .modern-header {
    background: #2f3133 !important;
    border-bottom: 1px solid #242628 !important;
    color: #f8fafc !important;
    box-shadow: none !important;
  }

  .modern-breadcrumb-item,
  .modern-breadcrumb-separator {
    color: #e5e7eb !important;
  }

  .modern-breadcrumb-item.active {
    color: #ffffff !important;
  }

  .modern-breadcrumb-item:hover,
  .modern-breadcrumb-item:focus-visible {
    color: #bfdbfe !important;
  }


  .modern-breadcrumb {
    gap: 10px !important;
    font-size: 0.86rem !important;
  }

  .modern-breadcrumb-item {
    gap: 6px !important;
    line-height: 1 !important;
    font-size: 0.86rem !important;
    font-weight: 650 !important;
  }

  .modern-breadcrumb-item i {
    width: 16px !important;
    min-width: 16px !important;
    margin-right: 0 !important;
    font-size: 0.82rem !important;
    text-align: center !important;
  }

  .modern-breadcrumb-separator {
    font-size: 0.72rem !important;
    opacity: 0.68 !important;
  }
  .modern-header-user-menu {
    color: #f8fafc !important;
    border-color: transparent !important;
  }

  .modern-header-user-menu:hover,
  .modern-header-user-menu:focus-visible,
  .modern-header-user-menu[aria-expanded="true"] {
    background: rgba(255, 255, 255, 0.08) !important;
    border-color: rgba(255, 255, 255, 0.18) !important;
  }

  .modern-header-username,
  .modern-header-user-role,
  .modern-header-dropdown-icon {
    color: #f8fafc !important;
  }

  .modern-header-user-role {
    opacity: 0.72;
  }

  .modern-header-avatar {
    border-color: rgba(255, 255, 255, 0.55) !important;
    background: #111827 !important;
  }

  .modern-user-dropdown {
    display: none;
    min-width: 220px !important;
    background: #ffffff !important;
    border: 1px solid #dfe3e8 !important;
    border-radius: 8px !important;
    box-shadow: 0 16px 36px rgba(15, 23, 42, 0.18) !important;
    padding: 6px !important;
    z-index: 2050 !important;
  }

  .modern-user-dropdown.show {
    display: block !important;
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
    transform: translateY(0) !important;
  }

  .modern-user-dropdown-item {
    min-height: 42px !important;
    color: #17202a !important;
    border-radius: 6px !important;
  }

  .modern-user-dropdown-item:hover,
  .modern-user-dropdown-item:focus-visible {
    background: #f3f6fb !important;
    color: #0f172a !important;
  }

  .modern-user-dropdown-item.logout {
    color: #b42318 !important;
  }
}

/* Phase 2 shell header baseline: visual only. */
@media (min-width: 1024px) {
  .modern-header {
    min-height: var(--enterprise-header-height) !important;
    padding: 0 22px !important;
    background: #2b2d30 !important;
    border-bottom-color: rgba(255, 255, 255, 0.08) !important;
  }

  .modern-header-left,
  .modern-header-right {
    min-height: var(--enterprise-header-height) !important;
  }

  .modern-breadcrumb-item {
    min-height: 40px !important;
    border-radius: 7px !important;
    padding: 0 2px !important;
  }

  .modern-breadcrumb-item:hover,
  .modern-breadcrumb-item:focus-visible {
    background: rgba(255, 255, 255, 0.06) !important;
    color: #ffffff !important;
  }

  .modern-header-user-menu {
    min-height: 48px !important;
    border-radius: 8px !important;
  }
}
/* Phase 4 shell import replacement: structural rules formerly supplied by modern-header.css. */
@media (min-width: 1024px) {
  .modern-header-left {
    display: flex !important;
    align-items: center !important;
    flex: 1 1 auto !important;
    min-width: 0 !important;
    gap: 14px !important;
  }

  .modern-header-right {
    display: flex !important;
    align-items: center !important;
    flex: 0 0 auto !important;
    gap: 10px !important;
  }

  .modern-mobile-menu-toggle,
  .modern-header-action-btn,
  .modern-notification-btn,
  .modern-header-divider {
    display: none !important;
  }

  .modern-header-user-menu {
    display: inline-flex !important;
    align-items: center !important;
    gap: 10px !important;
    background: transparent !important;
  }

  .modern-header-user-info {
    display: flex !important;
    flex-direction: column !important;
    align-items: flex-start !important;
    gap: 2px !important;
    min-width: 0 !important;
  }

  .modern-user-dropdown {
    position: absolute !important;
    top: calc(100% + 8px) !important;
    right: 0 !important;
  }

  .modern-user-dropdown-item {
    display: flex !important;
    align-items: center !important;
    gap: 10px !important;
    width: 100% !important;
    padding: 9px 11px !important;
    text-decoration: none !important;
    font-size: 12px !important;
    font-weight: 750 !important;
  }

  .modern-user-dropdown-item i {
    width: 18px !important;
    text-align: center !important;
  }

  .modern-user-dropdown-divider {
    margin: 6px 0 !important;
    border-color: #e5e7eb !important;
  }
}
/* Phase 4 regression fix: restore fixed header geometry after removing modern-header.css. */
@media (min-width: 1024px) {
  .modern-header {
    position: fixed !important;
    top: 0 !important;
    right: 0 !important;
    left: var(--enterprise-sidebar-width) !important;
    z-index: 1020 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    box-sizing: border-box !important;
    width: auto !important;
  }

  .sidebar.collapsed ~ .modern-header {
    left: var(--enterprise-sidebar-collapsed-width) !important;
  }
}