/**
 * Sophia College Design System CSS
 * Version 2.1 - Optimized
 * 
 * PURPOSE: Extends unified-base.css with component-specific utilities
 * LOAD ORDER: Should be loaded AFTER unified-base.css
 * 
 * This file provides:
 * - Additional utility classes (buttons, animations, loading states)
 * - Component-specific styling (focus indicators, skeletons, empty states)
 * - Enhanced accessibility features (WCAG 2.1 AA compliant)
 * 
 * ⚠️ IMPORTANT: All CSS variables are now centralized in unified-base.css
 * Do NOT add duplicate variable definitions here. Reference existing variables only.
 * 
 * Available variables include:
 * - Brand colors: --brand-navy, --brand-maroon, --primary-navy, --primary-maroon, etc.
 * - Semantic colors: --success, --warning, --danger, --info
 * - Spacing: --space-xs through --space-12
 * - Typography: --text-xs through --text-3xl
 * - Shadows: --shadow-xs through --shadow-xl
 * - Border radius: --radius-sm through --radius-full
 */

:root {
  /* Component-specific variables (not defined in unified-base.css) */
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;
}

/* Utility Classes */

/* Spacing Utilities */
.p-xs { padding: var(--space-xs); }
.p-sm { padding: var(--space-sm); }
.p-md { padding: var(--space-md); }
.p-lg { padding: var(--space-lg); }
.p-xl { padding: var(--space-xl); }

.m-xs { margin: var(--space-xs); }
.m-sm { margin: var(--space-sm); }
.m-md { margin: var(--space-md); }
.m-lg { margin: var(--space-lg); }
.m-xl { margin: var(--space-xl); }

/* Text Utilities */
.text-xs { font-size: var(--text-xs); }
.text-sm { font-size: var(--text-sm); }
.text-base { font-size: var(--text-base); }
.text-lg { font-size: var(--text-lg); }
.text-xl { font-size: var(--text-xl); }

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.font-normal { font-weight: 400; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

/* Color Utilities */
.text-primary { color: var(--primary-navy); }
.text-accent { color: var(--primary-maroon); }
.text-success { color: var(--success); }
.text-warning { color: var(--warning); }
.text-danger { color: var(--danger); }
.text-info { color: var(--info); }

.bg-primary { background-color: var(--primary-navy); }
.bg-accent { background-color: var(--primary-maroon); }
.bg-light { background-color: var(--light-gray); }
.bg-white { background-color: var(--white); }

/* Border Utilities */
.border { border: 1px solid #e2e8f0; }
.border-primary { border-color: var(--primary-navy); }
.border-accent { border-color: var(--primary-maroon); }

.rounded { border-radius: var(--radius-md); }
.rounded-sm { border-radius: var(--radius-sm); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }

/* Shadow Utilities */
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }

/* Layout Utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-row { flex-direction: row; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }

.grid { display: grid; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }

.hidden { display: none; }
.block { display: block; }
.inline-block { display: inline-block; }

/* Responsive Utilities */
@media (max-width: 768px) {
  .md\:hidden { display: none; }
  .md\:block { display: block; }
  .md\:flex { display: flex; }
}

@media (max-width: 640px) {
  .sm\:hidden { display: none; }
  .sm\:block { display: block; }
  .sm\:text-sm { font-size: var(--text-sm); }
  .sm\:p-sm { padding: var(--space-sm); }
}

/* ===== ENHANCED BUTTON SYSTEM ===== */
.btn-modern {
  background: var(--primary-maroon);
  color: var(--white);
  border: none;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.btn-modern:hover {
  background: #550000;
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.btn-warning {
  background: var(--warning);
  color: var(--dark-gray);
}

.btn-warning:hover {
  background: #d97706;
}

.btn-danger {
  background: var(--danger);
  color: var(--white);
}

.btn-danger:hover {
  background: #b91c1c;
}

.btn-success {
  background: var(--success);
  color: var(--white);
}

.btn-success:hover {
  background: #047857;
}

.quick-action-btn {
  background: var(--primary-maroon);
  color: var(--white);
  border: none;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.quick-action-btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* Enhanced Animation Classes */
.hover-lift:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.click-shrink:active {
  transform: scale(0.98);
}

/* Migration Notice Component */
.migration-notice {
  background: linear-gradient(135deg, var(--info), #1d4ed8);
  color: var(--white);
  margin-bottom: var(--space-lg);
  padding: var(--space-md);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.migration-notice h4 {
  margin: 0;
  font-weight: 600;
  font-size: var(--text-lg);
}

.migration-notice p {
  margin: var(--space-xs) 0 0 0;
  opacity: 0.9;
  font-size: var(--text-sm);
}

.migration-notice .flex {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.migration-notice .icon {
  font-size: var(--text-2xl);
}

/* ===== ERROR STATES AND LOADING COMPONENTS ===== */
.system-error {
  position: fixed;
  top: 10px;
  right: 10px;
  background: linear-gradient(135deg, #ef4444, #dc2626);
  color: var(--white);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  z-index: 10000;
  box-shadow: var(--shadow-lg);
  max-width: 300px;
}

.system-error-title {
  font-weight: bold;
  margin-bottom: var(--space-sm);
}

.system-error-message {
  font-size: var(--text-sm);
  margin-bottom: var(--space-sm);
}

.retry-btn {
  background: rgba(255,255,255,0.2);
  border: none;
  color: var(--white);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: var(--text-sm);
  transition: var(--transition-fast);
}

.retry-btn:hover {
  background: rgba(255,255,255,0.3);
}

/* ===== STANDARDIZED LOADING SYSTEM ===== */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  backdrop-filter: blur(4px);
}

.loading-state {
  text-align: center;
  padding: var(--space-2xl);
  color: var(--medium-gray);
  min-height: 300px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--light-gray), #f1f5f9);
  border-radius: var(--radius-lg);
  border: 1px solid var(--medium-gray);
}

.loading-spinner {
  border: 4px solid var(--medium-gray);
  border-top: 4px solid var(--primary-navy);
  border-radius: 50%;
  width: 48px;
  height: 48px;
  animation: spin 1s linear infinite;
  margin: 0 auto var(--space-lg);
}

.loading-text {
  font-size: var(--text-base);
  color: var(--medium-gray);
  margin-top: var(--space-md);
}

.loading-status {
  background: var(--white);
  color: var(--dark-gray);
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  margin: var(--space-lg) auto;
  max-width: 400px;
  border: 1px solid var(--medium-gray);
  text-align: center;
}

.loading-status .loading-spinner {
  width: 24px;
  height: 24px;
  border-width: 3px;
  margin: 0 auto var(--space-sm);
}

/* Standard animations */
@keyframes spin {
  to { transform: rotate(360deg); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideInDown {
  from {
    transform: translateY(-100%);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
  40% { transform: translateY(-10px); }
  60% { transform: translateY(-5px); }
}

/* ===== COMPREHENSIVE ANIMATION LIBRARY ===== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-100%);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(100%);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(100%);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

@keyframes pulse-red {
  0% { background-color: #dc3545; }
  50% { background-color: #ff6b6b; }
  100% { background-color: #dc3545; }
}

@keyframes shimmer {
  0% { background-position: -200px 0; }
  100% { background-position: calc(200px + 100%) 0; }
}

@keyframes glow {
  0% { box-shadow: 0 0 5px currentColor; }
  50% { box-shadow: 0 0 20px currentColor, 0 0 30px currentColor; }
  100% { box-shadow: 0 0 5px currentColor; }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

@keyframes dropdownFadeIn {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes loading-skeleton {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* Animation utility classes */
.animate-fadeIn { animation: fadeIn var(--transition-fast); }
.animate-fadeInUp { animation: fadeInUp var(--transition-normal); }
.animate-fadeInDown { animation: fadeInDown var(--transition-normal); }
.animate-slideInLeft { animation: slideInLeft var(--transition-normal); }
.animate-slideInRight { animation: slideInRight var(--transition-normal); }
.animate-slideInUp { animation: slideInUp var(--transition-normal); }
.animate-slideInDown { animation: slideInDown var(--transition-normal); }
.animate-scaleIn { animation: scaleIn var(--transition-fast); }
.animate-pulse { animation: pulse 2s infinite; }
.animate-spin { animation: spin 1s linear infinite; }
.animate-bounce { animation: bounce 2s infinite; }
.animate-shake { animation: shake 0.5s ease-in-out; }

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
  .animate-fadeIn,
  .animate-fadeInUp,
  .animate-fadeInDown,
  .animate-slideInLeft,
  .animate-slideInRight,
  .animate-slideInUp,
  .animate-slideInDown,
  .animate-scaleIn,
  .animate-pulse,
  .animate-spin,
  .animate-bounce,
  .animate-shake {
    animation: none;
  }
}

/* ===== ENHANCED FOCUS INDICATORS (WCAG 2.4.7) ===== */
/* High-contrast, visible focus states for keyboard navigation */
*:focus {
  outline: 3px solid var(--primary-navy);
  outline-offset: 2px;
}

*:focus:not(:focus-visible) {
  outline: none;
}

*:focus-visible {
  outline: 3px solid var(--primary-navy);
  outline-offset: 2px;
  box-shadow: 0 0 0 4px rgba(0, 48, 87, 0.1);
}

/* Special focus states for interactive elements */
button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid var(--primary-navy);
  outline-offset: 2px;
  box-shadow: 0 0 0 5px rgba(0, 48, 87, 0.15);
  z-index: 1;
}

/* Card focus states */
.card:focus-visible,
.modern-card:focus-visible {
  outline: 3px solid var(--primary-navy);
  outline-offset: 3px;
  box-shadow: 0 0 0 6px rgba(0, 48, 87, 0.1), var(--shadow-lg);
  transform: translateY(-2px);
}

/* Tab focus states */
.tab-button:focus-visible {
  outline: 3px solid var(--primary-navy);
  outline-offset: -3px;
  background: rgba(0, 48, 87, 0.1);
}

/* Dropdown menu focus states */
.dropdown-content a:focus-visible,
.dropdown-content button:focus-visible {
  outline: 2px solid var(--primary-navy);
  outline-offset: -2px;
  background: var(--light-gray);
}

/* Skip to content link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--primary-navy);
  color: var(--white);
  padding: var(--space-sm) var(--space-md);
  text-decoration: none;
  z-index: 100;
  border-radius: 0 0 var(--radius-md) 0;
  font-weight: 600;
}

.skip-link:focus {
  top: 0;
  outline: 3px solid var(--accent-gold);
  outline-offset: 2px;
}

/* ===== LOADING SKELETON SCREENS ===== */
/* Better perceived performance than spinners */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--light-gray) 0%,
    #f0f0f0 20%,
    var(--light-gray) 40%,
    var(--light-gray) 100%
  );
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s ease-in-out infinite;
  border-radius: var(--radius-sm);
}

.skeleton-text {
  height: 1em;
  margin-bottom: var(--space-xs);
}

.skeleton-text:last-child {
  width: 80%;
}

.skeleton-heading {
  height: 1.5em;
  margin-bottom: var(--space-sm);
}

.skeleton-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
}

.skeleton-card {
  padding: var(--space-lg);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-md);
}

.skeleton-table-row {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-md);
  border-bottom: 1px solid var(--border-light);
}

.skeleton-table-cell {
  flex: 1;
  height: 1em;
}

@keyframes skeleton-loading {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}

/* ===== EMPTY STATE ENHANCEMENTS ===== */
.empty-state {
  text-align: center;
  padding: var(--space-2xl);
  color: var(--text-secondary);
}

.empty-state-icon {
  font-size: 3rem;
  margin-bottom: var(--space-md);
  opacity: 0.5;
}

.empty-state-title {
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}

.empty-state-message {
  font-size: var(--text-base);
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
  line-height: var(--line-height-base);
}

.empty-state-action {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  background: var(--primary-maroon);
  color: var(--white);
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-fast);
  text-decoration: none;
}

.empty-state-action:hover {
  background: #550000;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.empty-state-action:focus-visible {
  outline: 3px solid var(--primary-navy);
  outline-offset: 2px;
}

/* ===== IMAGE OPTIMIZATION UTILITIES ===== */
/* Note: Removed global lazy loading background to preserve transparency */
/* Only apply backgrounds to specific classes that need loading placeholders */

.student-photo {
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-md);
  /* Note: No background color to preserve image transparency */
}

.student-photo[loading="lazy"] {
  min-height: 200px;
  background: var(--light-gray); /* Only show background while loading */
}

/* Fade in effect for lazy loaded images */
img.loaded {
  animation: fadeIn var(--transition-fast);
}