/**
 * PREMIUM NAVIGATION SYSTEM
 * Rechnung.best - Market-Leading Navigation Design
 * Inspired by: Stripe Dashboard, Linear, Notion, Figma
 *
 * VERSION: 1.0.0
 * CREATED: 2025-12-22
 */

/* ============================================
   DESIGN TOKENS - NAVIGATION SYSTEM
   ============================================ */

:root {
  /* Sidebar Dimensions */
  --sidebar-width: 260px;
  --sidebar-collapsed-width: 72px;
  --sidebar-header-height: 64px;
  --sidebar-footer-height: 72px;
  --sidebar-item-height: 40px;

  /* Transitions */
  --nav-transition-duration: 200ms;
  --nav-transition-easing: cubic-bezier(0.4, 0, 0.2, 1);
  --nav-spring: cubic-bezier(0.34, 1.56, 0.64, 1);

  /* Background & Surface Colors */
  --sidebar-bg: #FAFBFC;
  --sidebar-bg-hover: #F3F4F6;
  --sidebar-bg-active: #EEF2FF;
  --sidebar-border: #E5E7EB;

  /* Text Colors */
  --sidebar-text-primary: #1F2937;
  --sidebar-text-secondary: #6B7280;
  --sidebar-text-muted: #9CA3AF;
  --sidebar-text-active: #2563eb;
  --sidebar-text-hover: #111827;

  /* Accent Colors - Unified with button system (#2563eb) */
  --sidebar-accent: #2563eb;
  --sidebar-accent-light: #dbeafe;
  --sidebar-accent-glow: rgba(37, 99, 235, 0.15);

  /* Icon Sizing */
  --sidebar-icon-size: 20px;
  --sidebar-icon-gap: 12px;

  /* Border Radius */
  --sidebar-radius-sm: 6px;
  --sidebar-radius-md: 8px;
  --sidebar-radius-lg: 12px;

  /* Shadows */
  --sidebar-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.04), 0 1px 2px -1px rgba(0, 0, 0, 0.04);
  --sidebar-shadow-active: 0 0 0 1px rgba(37, 99, 235, 0.1), 0 1px 3px 0 rgba(37, 99, 235, 0.1);

  /* Mobile Navigation */
  --mobile-nav-height: 72px;
  --mobile-nav-bg: rgba(255, 255, 255, 0.95);
  --mobile-fab-size: 56px;
  --mobile-safe-area: env(safe-area-inset-bottom, 0px);
}

/* ============================================
   PREMIUM DESKTOP SIDEBAR
   ============================================ */

.premium-sidebar {
  position: fixed;
  left: 0;
  top: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--sidebar-border);
  display: flex;
  flex-direction: column;
  z-index: 100;
  overflow: hidden;
  box-shadow: var(--sidebar-shadow);
  transition: width var(--nav-transition-duration) var(--nav-transition-easing);
  backdrop-filter: blur(var(--rb-glass-blur, 20px)) saturate(var(--rb-glass-saturate, 1.8));
  -webkit-backdrop-filter: blur(var(--rb-glass-blur, 20px)) saturate(var(--rb-glass-saturate, 1.8));
}

/* Sidebar Header */
.premium-sidebar-header {
  display: flex;
  align-items: center;
  height: var(--sidebar-header-height);
  padding: 0 20px;
  border-bottom: 1px solid var(--sidebar-border);
  flex-shrink: 0;
}

.premium-sidebar-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--sidebar-text-primary);
  transition: opacity var(--nav-transition-duration) ease;
}

.premium-sidebar-logo:hover {
  opacity: 0.85;
}

.premium-logo-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
  border-radius: 10px;
  color: white;
  flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

.premium-logo-icon svg {
  width: 20px;
  height: 20px;
}

.premium-logo-text {
  -apple-system, -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  color: var(--sidebar-text-primary);
}

/* Sidebar Navigation Container */
.premium-sidebar-nav {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 16px 0;
  scrollbar-width: thin;
  scrollbar-color: var(--sidebar-border) transparent;
}

.premium-sidebar-nav::-webkit-scrollbar {
  width: 4px;
}

.premium-sidebar-nav::-webkit-scrollbar-track {
  background: transparent;
}

.premium-sidebar-nav::-webkit-scrollbar-thumb {
  background-color: var(--sidebar-border);
  border-radius: 2px;
}

.premium-sidebar-nav::-webkit-scrollbar-thumb:hover {
  background-color: var(--sidebar-text-muted);
}

/* Navigation Sections */
.premium-nav-section {
  margin-bottom: 12px;
}

.premium-nav-section:last-child {
  margin-bottom: 0;
}

.premium-nav-section-title {
  display: flex;
  align-items: center;
  padding: 8px 20px;
  -apple-system, -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--sidebar-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  user-select: none;
}

/* Navigation Menu */
.premium-nav-menu {
  list-style: none;
  margin: 0;
  padding: 0 8px;
}

/* Navigation Items */
.premium-nav-item {
  margin: 2px 0;
}

.premium-nav-link {
  display: flex;
  align-items: center;
  gap: var(--sidebar-icon-gap);
  padding: 10px 12px;
  min-height: var(--sidebar-item-height);
  border-radius: var(--sidebar-radius-md);
  text-decoration: none;
  color: var(--sidebar-text-secondary);
  -apple-system, -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  position: relative;
  cursor: pointer;
  transition:
    background-color var(--nav-transition-duration) ease,
    color var(--nav-transition-duration) ease,
    transform 100ms ease;
  outline: none;
}

/* Nav Icon */
.premium-nav-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--sidebar-icon-size);
  height: var(--sidebar-icon-size);
  flex-shrink: 0;
  color: inherit;
  opacity: 0.7;
  transition: opacity var(--nav-transition-duration) ease;
}

.premium-nav-icon svg {
  width: 100%;
  height: 100%;
  stroke-width: 1.75;
}

/* Nav Text */
.premium-nav-text {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Hover State */
.premium-nav-link:hover {
  background-color: var(--sidebar-bg-hover);
  color: var(--sidebar-text-hover);
  transform: translateX(2px);
}

.premium-nav-link:hover .premium-nav-icon {
  opacity: 1;
}

/* Active State */
.premium-nav-link.active {
  background-color: var(--sidebar-accent-light);
  color: var(--sidebar-accent);
  font-weight: 600;
  box-shadow: var(--sidebar-shadow-active);
}

.premium-nav-link.active .premium-nav-icon {
  opacity: 1;
  color: var(--sidebar-accent);
}

/* Active Indicator Bar */
.premium-nav-link.active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 20px;
  background: linear-gradient(180deg, #2563eb, #7c3aed);
  border-radius: 0 3px 3px 0;
  box-shadow: 0 0 10px rgba(37, 99, 235, 0.3);
}

/* Focus State */
.premium-nav-link:focus-visible {
  outline: 2px solid var(--sidebar-accent);
  outline-offset: -2px;
  background-color: var(--sidebar-bg-hover);
}

/* Pressed State */
.premium-nav-link:active {
  transform: translateX(0) scale(0.98);
  transition-duration: 50ms;
}

/* Badges */
.premium-nav-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 20px;
  height: 20px;
  padding: 0 6px;
  margin-left: auto;
  background: var(--sidebar-accent);
  color: white;
  font-size: 0.6875rem;
  font-weight: 600;
  border-radius: 10px;
  line-height: 1;
}

.premium-nav-badge.new {
  background: linear-gradient(135deg, #10B981 0%, #059669 100%);
}

.premium-nav-badge.warning {
  background: linear-gradient(135deg, #F59E0B 0%, #D97706 100%);
}

/* Dot Indicator */
.premium-nav-dot {
  width: 8px;
  height: 8px;
  background: var(--sidebar-accent);
  border-radius: 50%;
  margin-left: auto;
  animation: dot-pulse 2s ease-in-out infinite;
}

@keyframes dot-pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(1.15); }
}

/* Divider */
.premium-nav-divider {
  height: 1px;
  background: var(--sidebar-border);
  margin: 8px 20px;
}

/* Help Link - Special Styling */
.premium-nav-link.premium-nav-help {
  color: #10B981;
}

.premium-nav-link.premium-nav-help .premium-nav-icon {
  color: #10B981;
  opacity: 1;
}

.premium-nav-link.premium-nav-help:hover {
  background-color: rgba(16, 185, 129, 0.1);
  color: #059669;
}

.premium-nav-link.premium-nav-help:hover .premium-nav-icon {
  color: #059669;
}

/* Sidebar Footer */
.premium-sidebar-footer {
  flex-shrink: 0;
  border-top: 1px solid var(--sidebar-border);
  padding: 12px;
}

.premium-user-profile {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--sidebar-radius-md);
  cursor: pointer;
  transition: background-color var(--nav-transition-duration) ease;
}

.premium-user-profile:hover {
  background-color: var(--sidebar-bg-hover);
}

.premium-user-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--sidebar-accent) 0%, #1d4ed8 100%);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  -apple-system, sans-serif;
  font-size: 0.875rem;
  font-weight: 600;
  flex-shrink: 0;
}

.premium-user-info {
  flex: 1;
  min-width: 0;
}

.premium-user-name {
  -apple-system, sans-serif;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--sidebar-text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.premium-user-role {
  font-size: 0.75rem;
  color: var(--sidebar-text-muted);
}

.premium-user-menu-icon {
  width: 16px;
  height: 16px;
  color: var(--sidebar-text-muted);
  flex-shrink: 0;
}

/* ============================================
   PREMIUM MOBILE NAVIGATION
   ============================================ */

/* Mobile Bottom Navigation */
.premium-mobile-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: calc(var(--mobile-nav-height) + var(--mobile-safe-area));
  padding-bottom: var(--mobile-safe-area);
  background: var(--mobile-nav-bg);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border-top: 1px solid rgba(0, 0, 0, 0.06);
  box-shadow: 0 -4px 24px rgba(0, 0, 0, 0.08);
  z-index: 1000;
}

.premium-mobile-nav-container {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  height: var(--mobile-nav-height);
  padding: 0 8px;
  align-items: center;
}

.premium-mobile-nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  height: 100%;
  min-height: 48px;
  min-width: 48px;
  padding: 8px 12px;
  color: var(--sidebar-text-muted);
  text-decoration: none;
  border: none;
  background: transparent;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  transition: color var(--nav-transition-duration) ease;
}

.premium-mobile-nav-item:hover,
.premium-mobile-nav-item:focus-visible {
  color: var(--sidebar-accent);
}

.premium-mobile-nav-item.active {
  color: var(--sidebar-accent);
}

.premium-mobile-nav-icon {
  width: 24px;
  height: 24px;
  transition: transform var(--nav-transition-duration) var(--nav-spring);
}

.premium-mobile-nav-item.active .premium-mobile-nav-icon {
  transform: scale(1.1);
}

.premium-mobile-nav-label {
  -apple-system, sans-serif;
  font-size: 0.625rem;
  font-weight: 500;
  letter-spacing: 0.02em;
}

/* FAB Button */
.premium-mobile-fab {
  position: relative;
  width: var(--mobile-fab-size);
  height: var(--mobile-fab-size);
  margin-top: -24px;
  background: linear-gradient(135deg, var(--sidebar-accent) 0%, #1d4ed8 100%);
  border-radius: 16px;
  border: none;
  color: white;
  cursor: pointer;
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.4);
  transition:
    transform var(--nav-transition-duration) var(--nav-spring),
    box-shadow var(--nav-transition-duration) ease;
  -webkit-tap-highlight-color: transparent;
}

.premium-mobile-fab:hover {
  transform: scale(1.05);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.5);
}

.premium-mobile-fab:active {
  transform: scale(0.95);
}

.premium-mobile-fab:focus-visible {
  outline: 2px solid white;
  outline-offset: 2px;
  box-shadow: 0 0 0 4px var(--sidebar-accent-glow), 0 4px 16px rgba(37, 99, 235, 0.4);
}

.premium-mobile-fab-icon {
  width: 28px;
  height: 28px;
  transition: transform var(--nav-transition-duration) ease;
}

.premium-mobile-fab[aria-expanded="true"] .premium-mobile-fab-icon {
  transform: rotate(45deg);
}

/* Mobile Header */
.premium-mobile-header {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 60px;
  padding: 0 16px;
  background: var(--mobile-nav-bg);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  z-index: 1000;
  align-items: center;
  justify-content: space-between;
}

.premium-hamburger {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  color: var(--sidebar-text-primary);
  -webkit-tap-highlight-color: transparent;
  transition: background-color var(--nav-transition-duration) ease;
}

.premium-hamburger:hover {
  background-color: var(--sidebar-bg-hover);
}

.premium-hamburger svg {
  width: 24px;
  height: 24px;
}

.premium-mobile-title {
  -apple-system, sans-serif;
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--sidebar-text-primary);
  letter-spacing: -0.02em;
}

.premium-mobile-user-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--sidebar-accent) 0%, #1d4ed8 100%);
  border: none;
  color: white;
  -apple-system, sans-serif;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

/* Mobile Slide Menu */
.premium-mobile-menu {
  position: fixed;
  top: 0;
  left: 0;
  width: min(85vw, 320px);
  height: 100vh;
  background: white;
  z-index: 2000;
  transform: translateX(-100%);
  transition: transform 300ms cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 4px 0 24px rgba(0, 0, 0, 0.15);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

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

.premium-mobile-menu-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 1999;
  opacity: 0;
  visibility: hidden;
  transition:
    opacity 300ms ease,
    visibility 300ms ease;
}

.premium-mobile-menu-backdrop.visible {
  opacity: 1;
  visibility: visible;
}

.premium-mobile-menu-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--sidebar-border);
}

.premium-mobile-menu-close {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  color: var(--sidebar-text-secondary);
  transition: background-color var(--nav-transition-duration) ease;
  -webkit-tap-highlight-color: transparent;
}

.premium-mobile-menu-close:hover {
  background-color: var(--sidebar-bg-hover);
}

.premium-mobile-menu-nav {
  flex: 1;
  overflow-y: auto;
  padding: 16px 0;
}

.premium-mobile-menu-section {
  margin-bottom: 20px;
}

.premium-mobile-menu-section-title {
  padding: 8px 20px;
  -apple-system, sans-serif;
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--sidebar-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.premium-mobile-menu-list {
  list-style: none;
  margin: 0;
  padding: 0 12px;
}

.premium-mobile-menu-item {
  margin: 2px 0;
}

.premium-mobile-menu-link {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 12px;
  min-height: 52px;
  border-radius: 12px;
  text-decoration: none;
  color: var(--sidebar-text-secondary);
  -apple-system, sans-serif;
  font-size: 1rem;
  font-weight: 500;
  transition:
    background-color var(--nav-transition-duration) ease,
    color var(--nav-transition-duration) ease;
  -webkit-tap-highlight-color: transparent;
}

.premium-mobile-menu-link:hover,
.premium-mobile-menu-link:active {
  background-color: var(--sidebar-bg-hover);
  color: var(--sidebar-text-hover);
}

.premium-mobile-menu-link.active {
  background-color: var(--sidebar-accent-light);
  color: var(--sidebar-accent);
  font-weight: 600;
}

.premium-mobile-menu-icon {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  opacity: 0.8;
}

.premium-mobile-menu-link.active .premium-mobile-menu-icon {
  opacity: 1;
}

.premium-mobile-menu-footer {
  border-top: 1px solid var(--sidebar-border);
  padding: 16px 12px;
  padding-bottom: calc(16px + var(--mobile-safe-area));
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.premium-mobile-logout-btn {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 12px;
  width: 100%;
  border-radius: 12px;
  border: none;
  background: #FEE2E2;
  color: #DC2626;
  font-family: -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: background-color var(--nav-transition-duration) ease;
  -webkit-tap-highlight-color: transparent;
}

.premium-mobile-logout-btn:hover,
.premium-mobile-logout-btn:active {
  background: #FECACA;
}

.premium-mobile-logout-btn .premium-mobile-menu-icon {
  color: #DC2626;
}

/* FAB Quick Menu */
.premium-fab-menu {
  position: fixed;
  bottom: calc(var(--mobile-nav-height) + var(--mobile-safe-area) + 16px);
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: white;
  border-radius: 20px;
  padding: 20px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
  z-index: 1500;
  opacity: 0;
  visibility: hidden;
  transition:
    opacity 200ms ease,
    transform 200ms var(--nav-spring),
    visibility 200ms ease;
}

.premium-fab-menu.visible {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.premium-fab-menu-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.premium-fab-menu-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 16px 12px;
  min-width: 80px;
  background: var(--sidebar-bg);
  border-radius: 14px;
  border: none;
  text-decoration: none;
  color: var(--sidebar-text-secondary);
  cursor: pointer;
  transition:
    background-color var(--nav-transition-duration) ease,
    transform 100ms ease;
  -webkit-tap-highlight-color: transparent;
}

.premium-fab-menu-item:hover {
  background: var(--sidebar-bg-hover);
}

.premium-fab-menu-item:active {
  transform: scale(0.95);
  background: var(--sidebar-accent-light);
}

.premium-fab-menu-item-icon {
  width: 28px;
  height: 28px;
  color: var(--sidebar-accent);
}

.premium-fab-menu-item-label {
  -apple-system, sans-serif;
  font-size: 0.75rem;
  font-weight: 500;
  text-align: center;
}

/* ============================================
   RESPONSIVE BREAKPOINTS
   ============================================ */

@media (max-width: 1024px) {
  .premium-sidebar {
    width: 220px;
  }

  .main-content {
    margin-left: 220px;
  }
}

@media (max-width: 768px) {
  /* Hide desktop sidebar */
  .premium-sidebar {
    display: none;
  }

  /* Show mobile navigation */
  .premium-mobile-nav,
  .premium-mobile-header {
    display: flex;
  }

  /* Adjust main content */
  .main-content {
    margin-left: 0;
    padding-top: 76px;
    padding-bottom: calc(var(--mobile-nav-height) + var(--mobile-safe-area) + 16px);
  }
}

/* ============================================
   NAV LOCKED STATES - Feature Gating
   ============================================ */

/* Desktop Sidebar - Locked Nav Items */
.premium-nav-link.nav-locked {
  opacity: 0.42;
  cursor: not-allowed;
  transition:
    opacity 200ms ease,
    background-color 200ms ease;
}

.premium-nav-link.nav-locked .premium-nav-icon {
  opacity: 0.3;
  filter: grayscale(100%);
}

.premium-nav-link.nav-locked .premium-nav-text {
  text-decoration: line-through;
  text-decoration-color: var(--sidebar-text-muted);
  text-decoration-thickness: 1px;
}

.premium-nav-link.nav-locked:hover {
  background-color: rgba(139, 92, 246, 0.06);
  transform: none;
  color: var(--sidebar-text-muted);
  opacity: 0.55;
}

.premium-nav-link.nav-locked:hover .premium-nav-icon {
  opacity: 0.35;
}

.premium-nav-link.nav-locked:hover .nav-upgrade-badge {
  transform: scale(1.12);
  box-shadow: 0 0 8px rgba(139, 92, 246, 0.4);
}

.premium-nav-link.nav-locked.active {
  background: none;
  color: var(--sidebar-text-muted);
  font-weight: 500;
  box-shadow: none;
}

.premium-nav-link.nav-locked.active::before {
  display: none;
}

.premium-nav-link.nav-locked.active .premium-nav-icon {
  color: var(--sidebar-text-muted);
  opacity: 0.4;
}

.premium-nav-link.nav-locked:active {
  transform: none;
  background-color: rgba(139, 92, 246, 0.08);
  transition-duration: 50ms;
}

/* Lock Icon (inline) */
.nav-locked-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  margin-left: auto;
  color: var(--sidebar-text-muted);
  opacity: 0.75;
  flex-shrink: 0;
  transition: opacity 200ms ease;
}

.nav-locked-icon svg {
  width: 100%;
  height: 100%;
}

/* PRO Upgrade Badge */
.nav-upgrade-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 20px;
  padding: 0 8px;
  margin-left: 6px;
  background: linear-gradient(135deg, #8B5CF6 0%, #6D28D9 100%);
  color: white;
  font-size: 0.625rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  border-radius: 10px;
  text-transform: uppercase;
  flex-shrink: 0;
  line-height: 1;
  box-shadow: 0 1px 4px rgba(109, 40, 217, 0.3);
  transition:
    transform 200ms ease,
    box-shadow 200ms ease;
}

/* Mobile Slide Menu - Locked Items */
.premium-mobile-menu-link.nav-locked {
  opacity: 0.42;
  cursor: not-allowed;
  transition: opacity 200ms ease, background-color 200ms ease;
}

.premium-mobile-menu-link.nav-locked .premium-mobile-menu-icon {
  opacity: 0.3;
  filter: grayscale(100%);
}

.premium-mobile-menu-link.nav-locked:hover {
  background: rgba(139, 92, 246, 0.06);
  color: var(--sidebar-text-muted);
  opacity: 0.52;
}

/* Tactile press feedback for locked items: brief purple flash confirms tap registered */
.premium-mobile-menu-link.nav-locked:active {
  background: rgba(139, 92, 246, 0.14);
  color: var(--sidebar-text-muted);
  opacity: 0.60;
  transition-duration: 50ms;
}

.premium-mobile-menu-link.nav-locked.active {
  background: none;
  color: var(--sidebar-text-muted);
  font-weight: 500;
}

.premium-mobile-menu-link.nav-locked .nav-locked-icon {
  width: 18px;
  height: 18px;
}

.premium-mobile-menu-link.nav-locked .nav-upgrade-badge {
  height: 22px;
  padding: 0 10px;
  font-size: 0.6875rem;
}

/* Mobile Bottom Nav - Locked Items */
.premium-mobile-nav-item.nav-locked {
  opacity: 0.5;
  cursor: not-allowed;
  position: relative;
}

.premium-mobile-nav-item.nav-locked.active {
  color: var(--sidebar-text-muted);
}

/* FAB Menu - Locked Items */
.premium-fab-menu-item.fab-item-locked {
  opacity: 0.38;
  cursor: not-allowed;
  position: relative;
  transition: opacity 200ms ease, background-color 200ms ease;
  /* Dashed border signals locked state even in bright sunlight / low-vision */
  border: 1.5px dashed var(--sidebar-text-muted);
}

.premium-fab-menu-item.fab-item-locked .premium-fab-menu-item-icon {
  filter: grayscale(100%);
  color: var(--sidebar-text-muted);
}

.premium-fab-menu-item.fab-item-locked .premium-fab-menu-item-label {
  text-decoration: line-through;
  text-decoration-color: var(--sidebar-text-muted);
}

.premium-fab-menu-item.fab-item-locked:hover {
  background: rgba(139, 92, 246, 0.06);
  opacity: 0.50;
}

/* Tactile press feedback: brief highlight confirms tap before modal */
.premium-fab-menu-item.fab-item-locked:active {
  transform: scale(0.97);
  background: rgba(139, 92, 246, 0.12);
  transition-duration: 50ms;
}

.fab-lock-indicator {
  position: absolute;
  top: 4px;
  right: 4px;
  width: 16px;
  height: 16px;
  color: #8B5CF6;
  opacity: 0.85;
  background: rgba(139, 92, 246, 0.12);
  border-radius: 50%;
  padding: 2px;
}

.fab-lock-indicator svg {
  width: 100%;
  height: 100%;
}

/* ============================================
   DARK MODE SUPPORT
   ============================================ */

@media (prefers-color-scheme: dark) {
  :root {
    --sidebar-bg: #18181B;
    --sidebar-bg-hover: #27272A;
    --sidebar-bg-active: rgba(99, 102, 241, 0.15);
    --sidebar-border: #3F3F46;

    --sidebar-text-primary: #FAFAFA;
    --sidebar-text-secondary: #A1A1AA;
    --sidebar-text-muted: #71717A;
    --sidebar-text-active: #60a5fa;
    --sidebar-text-hover: #FFFFFF;

    --sidebar-accent: #60a5fa;
    --sidebar-accent-light: rgba(96, 165, 250, 0.15);
    --sidebar-accent-glow: rgba(96, 165, 250, 0.2);

    --mobile-nav-bg: rgba(24, 24, 27, 0.95);
  }

  .premium-sidebar,
  .premium-mobile-menu {
    background: var(--sidebar-bg);
  }

  .premium-logo-icon {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
  }

  .premium-mobile-fab {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
  }

  .premium-fab-menu {
    background: var(--sidebar-bg);
  }

  .premium-fab-menu-item {
    background: #27272A;
  }

  /* Locked state dark mode */
  .nav-upgrade-badge {
    background: linear-gradient(135deg, #A78BFA 0%, #8B5CF6 100%);
    box-shadow: 0 1px 6px rgba(167, 139, 250, 0.35);
  }

  .premium-nav-link.nav-locked:hover {
    background-color: rgba(167, 139, 250, 0.08);
  }

  .premium-mobile-menu-link.nav-locked:hover,
  .premium-mobile-menu-link.nav-locked:active {
    background: rgba(167, 139, 250, 0.08);
  }

  .premium-fab-menu-item.fab-item-locked:hover,
  .premium-fab-menu-item.fab-item-locked:active {
    background: rgba(167, 139, 250, 0.08);
  }

  .fab-lock-indicator {
    color: #A78BFA;
    background: rgba(167, 139, 250, 0.18);
  }

  .premium-nav-link.nav-locked .premium-nav-text {
    text-decoration-color: #52525B;
  }
}

/* ============================================
   REDUCED MOTION SUPPORT
   ============================================ */

@media (prefers-reduced-motion: reduce) {
  .premium-nav-link,
  .premium-mobile-nav-item,
  .premium-mobile-fab,
  .premium-mobile-menu,
  .premium-fab-menu,
  .premium-nav-dot {
    animation: none !important;
    transition: none !important;
  }
}

/* ============================================
   PRINT STYLES - HIDE NAVIGATION
   ============================================ */

@media print {
  .premium-sidebar,
  .premium-mobile-nav,
  .premium-mobile-header,
  .premium-mobile-menu,
  .premium-mobile-menu-backdrop,
  .premium-fab-menu {
    display: none !important;
  }

  .main-content {
    margin-left: 0 !important;
    padding-top: 0 !important;
    padding-bottom: 0 !important;
  }
}