/**
 * app-nav-tabs.css
 * Main application navigation tabs
 *
 * Features:
 * - Horizontal tab navigation (Dashboard, Cases, AI Hub, Tools, Docs)
 * - Tier-gating with lock icons and upgrade prompts
 * - Active state indicator
 * - Responsive (stacks on mobile)
 * - Keyboard navigation (arrow keys)
 */

.app-nav-tabs {
  display: flex;
  align-items: center;
  gap: 0;
  background: var(--ev-surface-secondary, #0f1a2e);
  border-bottom: 1px solid var(--ev-border-subtle, #3c4454);
  padding: 0 1.5rem;
  overflow-x: auto;
  scroll-behavior: smooth;

  /* Scrollbar styling */
  scrollbar-width: thin;
  scrollbar-color: var(--ev-border-subtle, #3c4454) transparent;
}

.app-nav-tabs::-webkit-scrollbar {
  height: 4px;
}

.app-nav-tabs::-webkit-scrollbar-track {
  background: transparent;
}

.app-nav-tabs::-webkit-scrollbar-thumb {
  background: var(--ev-border-subtle, #3c4454);
  border-radius: 2px;
}

.app-nav-tabs::-webkit-scrollbar-thumb:hover {
  background: var(--ev-border-default, #6e7681);
}

/* Individual tab link */
.app-nav-tabs__link {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 1rem 1.25rem;
  color: var(--ev-text-secondary, #b0b9cc);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  transition: all 0.2s ease;
  position: relative;
  cursor: pointer;
}

.app-nav-tabs__link:hover {
  color: var(--ev-text-primary, #fff);
  background: rgb(88 166 255 / 5%);
}

.app-nav-tabs__link:focus {
  outline: 2px solid var(--ev-accent-primary, #58a6ff);
  outline-offset: -2px;
}

/* Active tab */
.app-nav-tabs__link[aria-current="page"] {
  color: var(--ev-accent-primary, #58a6ff);
  border-bottom-color: var(--ev-accent-primary, #58a6ff);
  background: rgb(88 166 255 / 8%);
}

/* Lock icon on tier-gated tabs */
.app-nav-tabs__lock-icon {
  width: 12px;
  height: 12px;
  margin-left: 0.25rem;
  opacity: 0.6;
}

.app-nav-tabs__link[data-tier-min]:not([aria-current="page"]) {
  cursor: not-allowed;
  opacity: 0.5;
}

.app-nav-tabs__link[data-tier-min]:hover {
  background: rgb(88 166 255 / 5%);
}

/* Tier-locked state with tooltip */
.app-nav-tabs__link[data-tier-min] .app-nav-tabs__lock-icon {
  opacity: 1;
}

.app-nav-tabs__link[data-tier-min]::after {
  content: attr(data-tier-tooltip);
  position: absolute;
  bottom: -32px;
  left: 50%;
  transform: translateX(-50%);
  padding: 0.5rem 0.75rem;
  background: var(--ev-surface-primary, #0a0e27);
  color: var(--ev-text-primary, #fff);
  font-size: 0.75rem;
  font-weight: 500;
  border-radius: 0.25rem;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
  border: 1px solid var(--ev-border-subtle, #3c4454);
  z-index: 10;
}

.app-nav-tabs__link[data-tier-min]:hover::after {
  opacity: 1;
}

/* Backdrop when tab is locked (prevent clicks) */
.app-nav-tabs__link[data-tier-min][disabled] {
  pointer-events: none;
}

/* Responsive adjustments */
@media (width <= 1024px) {
  .app-nav-tabs {
    padding: 0 1rem;
  }

  .app-nav-tabs__link {
    padding: 0.875rem 1rem;
    font-size: 0.9rem;
  }
}

@media (width <= 768px) {
  .app-nav-tabs {
    padding: 0 0.75rem;
    gap: 0.25rem;
  }

  .app-nav-tabs__link {
    padding: 0.75rem 0.875rem;
    font-size: 0.85rem;
  }

  /* Hide lock icon on mobile */
  .app-nav-tabs__lock-icon {
    display: none;
  }

  /* Remove tooltip on mobile */
  .app-nav-tabs__link[data-tier-min]::after {
    display: none;
  }
}

@media (width <= 640px) {
  .app-nav-tabs {
    padding: 0 0.5rem;
    justify-content: flex-start;
  }

  .app-nav-tabs__link {
    padding: 0.625rem 0.75rem;
    font-size: 0.8rem;
    border-bottom-width: 3px;
  }

  /* Reduce gap for smaller screens */
  .app-nav-tabs {
    gap: 0.1rem;
  }

  /* Allow text wrapping on very small screens */
  .app-nav-tabs__link {
    white-space: normal;
    max-width: 80px;
    text-align: center;
    line-height: 1.2;
  }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
  .app-nav-tabs,
  .app-nav-tabs__link {
    transition: none;
    scroll-behavior: auto;
  }

  .app-nav-tabs__link::after {
    transition: none;
  }
}

/* High contrast mode */
@media (prefers-contrast: more) {
  .app-nav-tabs {
    border-bottom-width: 2px;
  }

  .app-nav-tabs__link {
    border-bottom-width: 3px;
  }

  .app-nav-tabs__link:focus {
    outline-width: 3px;
  }
}

/* Focus visible for keyboard navigation */
.app-nav-tabs__link:focus:not(:focus-visible) {
  outline: none;
}

.app-nav-tabs__link:focus-visible {
  outline: 2px solid var(--ev-accent-primary, #58a6ff);
  outline-offset: -4px;
}