/* ==========================================================================
   FAB - FLOATING ACTION BUTTONS
   Fixed position buttons (bottom right)
   
   Original PLU Pattern:
   - Theme Toggle (Dark/Light)
   - Classroom Mode
   - Back to Top
   - Search (optional)
   ========================================================================== */

.fab-container {
  position: fixed;
  bottom: calc(1.5rem + env(safe-area-inset-bottom));
  right: 1.5rem;
  z-index: calc(var(--z-fixed) - 1);
  
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  
  /* Hidden on mobile when bottom nav is visible */
}

/* Mobile: Hide FAB buttons (moved to header) */
@media (max-width: 1023px) {
  .fab-container {
    display: none;
  }
}

/* Desktop: Show FAB buttons */
@media (min-width: 1024px) {
  .fab-container {
    display: flex;
  }
}

/* Individual FAB Button */
.fab-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  
  background: var(--glass-bg);
  backdrop-filter: var(--glass-backdrop);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-full);
  
  color: var(--text-primary);
  font-size: 1.25rem;
  
  cursor: pointer;
  transition: var(--transition-transform), var(--transition-shadow), background-color 0.2s ease;
  box-shadow: var(--shadow-lg);
  
  position: relative;
}

@media (min-width: 768px) {
  .fab-btn {
    width: 56px;
    height: 56px;
    font-size: 1.5rem;
  }
}

@media (hover: hover) {
  .fab-btn:hover {
    transform: translateY(-2px) scale(1.05);
    box-shadow: var(--shadow-xl);
    background: var(--bg-elevated);
  }
}

.fab-btn:active {
  transform: translateY(0) scale(0.98);
}

.fab-btn:focus-visible {
  outline: 2px solid var(--accent-primary);
  outline-offset: 2px;
}

/* Active State (for toggle buttons) */
.fab-btn.active {
  background: var(--accent-primary);
  color: white;
  border-color: transparent;
}

/* Back to Top - Hidden by default */
.fab-btn--backtop {
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
}

.fab-btn--backtop.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* Tooltip on hover */
.fab-btn::after {
  content: attr(data-tooltip);
  position: absolute;
  right: calc(100% + 12px);
  top: 50%;
  transform: translateY(-50%) translateX(10px);
  
  padding: 0.5rem 0.875rem;
  background: var(--bg-elevated);
  color: var(--text-primary);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  white-space: nowrap;
  border-radius: var(--radius-md);
  
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s ease, visibility 0.2s ease, transform 0.2s ease;
  pointer-events: none;
}

@media (hover: hover) {
  .fab-btn:hover::after {
    opacity: 1;
    visibility: visible;
    transform: translateY(-50%) translateX(0);
  }
}

/* Classroom Mode FAB */
.fab-btn--classroom.active {
  background: linear-gradient(135deg, var(--accent-pink), var(--accent-orange));
  animation: pulse-subtle 2s infinite;
}

@keyframes pulse-subtle {
  0%, 100% { box-shadow: 0 0 0 0 rgba(236, 72, 153, 0.4); }
  50% { box-shadow: 0 0 0 8px rgba(236, 72, 153, 0); }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  .fab-btn,
  .fab-btn--backtop {
    transition: none;
  }
  
  .fab-btn--classroom.active {
    animation: none;
  }
}