/**
 * Ligneclient Design System
 * Unified CSS variables, components, and accessibility styles
 */

/* ===========================================
   1. DESIGN TOKENS (CSS Variables)
   =========================================== */

:root {
  /* Primary Colors */
  --color-marine: #0a1628;
  --color-marine-light: #0f2240;
  --color-bleu-electrique: #2d7ff9;
  --color-bleu-electrique-hover: #1a6ee8;
  --color-cyan: #22d3ee;
  --color-cyan-dark: #0891b2;

  /* Neutral Colors */
  --color-white: #ffffff;
  --color-off-white: #faf9f7;
  --color-cream: #f5f4f0;
  --color-beige: #e7e5df;
  --color-gray-light: #d6d3d1;
  --color-gray-medium: #78716c;
  --color-gray-dark: #57534e;
  --color-charcoal: #292524;

  /* Semantic Colors */
  --color-success: #10b981;
  --color-success-light: #d1fae5;
  --color-warning: #f59e0b;
  --color-warning-light: #fef3c7;
  --color-error: #ef4444;
  --color-error-light: #fee2e2;
  --color-info: #3b82f6;
  --color-info-light: #dbeafe;

  /* Typography */
  --font-heading: 'Playfair Display', Georgia, serif;
  --font-body: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'SF Mono', Monaco, monospace;

  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;

  /* Line Heights */
  --leading-tight: 1.25;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;

  /* Spacing Scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
  --shadow-glow: 0 0 30px rgba(45, 127, 249, 0.3);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;

  /* Z-index Scale */
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-modal: 300;
  --z-toast: 400;

  /* Touch Target Minimum */
  --touch-target-min: 44px;
}

/* ===========================================
   2. ACCESSIBILITY & FOCUS STATES
   =========================================== */

/* Skip to main content link */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  z-index: var(--z-modal);
  padding: var(--space-3) var(--space-4);
  background: var(--color-marine);
  color: var(--color-white);
  border-radius: var(--radius-md);
  text-decoration: none;
  font-weight: 500;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-4);
  outline: 3px solid var(--color-bleu-electrique);
  outline-offset: 2px;
}

/* Focus visible styles for all interactive elements */
:focus {
  outline: none;
}

:focus-visible {
  outline: 3px solid var(--color-bleu-electrique);
  outline-offset: 2px;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid var(--color-bleu-electrique);
  outline-offset: 2px;
}

/* High contrast focus for dark backgrounds */
.dark-bg :focus-visible,
[data-theme="dark"] :focus-visible {
  outline-color: var(--color-cyan);
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* Screen reader only text */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ===========================================
   3. BUTTON COMPONENTS
   =========================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: var(--touch-target-min);
  padding: var(--space-3) var(--space-6);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 500;
  line-height: var(--leading-normal);
  text-decoration: none;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-base);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Primary Button */
.btn-primary {
  background: var(--color-bleu-electrique);
  color: var(--color-white);
}

.btn-primary:hover:not(:disabled) {
  background: var(--color-bleu-electrique-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-primary:active:not(:disabled) {
  transform: translateY(0);
}

/* Secondary Button */
.btn-secondary {
  background: var(--color-white);
  color: var(--color-marine);
  border: 2px solid var(--color-beige);
}

.btn-secondary:hover:not(:disabled) {
  border-color: var(--color-bleu-electrique);
  color: var(--color-bleu-electrique);
  transform: translateY(-2px);
}

/* Outline Button */
.btn-outline {
  background: transparent;
  color: var(--color-bleu-electrique);
  border: 2px solid var(--color-bleu-electrique);
}

.btn-outline:hover:not(:disabled) {
  background: var(--color-bleu-electrique);
  color: var(--color-white);
}

/* Ghost Button */
.btn-ghost {
  background: transparent;
  color: var(--color-gray-dark);
}

.btn-ghost:hover:not(:disabled) {
  background: var(--color-cream);
  color: var(--color-marine);
}

/* Button Sizes */
.btn-sm {
  min-height: 36px;
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
}

.btn-lg {
  min-height: 52px;
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-lg);
}

/* Button with Icon */
.btn-icon {
  min-width: var(--touch-target-min);
  padding: var(--space-3);
}

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

/* ===========================================
   4. FORM COMPONENTS
   =========================================== */

.form-group {
  margin-bottom: var(--space-6);
}

.form-label {
  display: block;
  margin-bottom: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-gray-dark);
}

.form-label-required::after {
  content: ' *';
  color: var(--color-error);
}

.form-input {
  display: block;
  width: 100%;
  min-height: var(--touch-target-min);
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-charcoal);
  background: var(--color-white);
  border: 2px solid var(--color-beige);
  border-radius: var(--radius-lg);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input::placeholder {
  color: var(--color-gray-medium);
}

.form-input:hover:not(:disabled) {
  border-color: var(--color-gray-light);
}

.form-input:focus {
  border-color: var(--color-bleu-electrique);
  box-shadow: 0 0 0 3px rgba(45, 127, 249, 0.1);
  outline: none;
}

/* Validation States */
.form-input[aria-invalid="true"],
.form-input.is-invalid {
  border-color: var(--color-error);
}

.form-input[aria-invalid="true"]:focus,
.form-input.is-invalid:focus {
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

.form-input.is-valid {
  border-color: var(--color-success);
}

.form-input.is-valid:focus {
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

/* Form Help Text */
.form-hint {
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-gray-medium);
}

.form-error {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-error);
}

.form-error::before {
  content: '';
  display: inline-block;
  width: 16px;
  height: 16px;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='%23ef4444'%3E%3Cpath fill-rule='evenodd' d='M18 10a8 8 0 11-16 0 8 8 0 0116 0zm-7 4a1 1 0 11-2 0 1 1 0 012 0zm-1-9a1 1 0 00-1 1v4a1 1 0 102 0V6a1 1 0 00-1-1z' clip-rule='evenodd'/%3E%3C/svg%3E") no-repeat center;
}

.form-success {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-success);
}

/* Checkbox & Radio */
.form-checkbox,
.form-radio {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  cursor: pointer;
}

.form-checkbox input,
.form-radio input {
  width: 20px;
  height: 20px;
  margin: 0;
  cursor: pointer;
  accent-color: var(--color-bleu-electrique);
}

/* ===========================================
   5. MOBILE NAVIGATION (Hamburger Menu)
   =========================================== */

.mobile-menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: var(--touch-target-min);
  height: var(--touch-target-min);
  padding: 0;
  background: transparent;
  border: none;
  cursor: pointer;
}

.mobile-menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: all var(--transition-base);
}

.mobile-menu-toggle .hamburger {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

/* Hamburger to X animation */
.mobile-menu-toggle[aria-expanded="true"] .hamburger span:nth-child(1) {
  transform: rotate(45deg) translate(6px, 6px);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}

/* Mobile Menu Panel */
.mobile-menu {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: var(--z-modal);
  background: var(--color-white);
  padding: var(--space-20) var(--space-6) var(--space-6);
  overflow-y: auto;
  transform: translateX(100%);
  transition: transform var(--transition-slow);
}

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

.mobile-menu-nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.mobile-menu-nav a {
  display: flex;
  align-items: center;
  min-height: var(--touch-target-min);
  padding: var(--space-4);
  font-size: var(--text-lg);
  font-weight: 500;
  color: var(--color-charcoal);
  text-decoration: none;
  border-radius: var(--radius-lg);
  transition: background var(--transition-fast);
}

.mobile-menu-nav a:hover,
.mobile-menu-nav a:focus {
  background: var(--color-cream);
}

.mobile-menu-close {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
}

@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: flex;
  }

  .mobile-menu {
    display: block;
  }

  .desktop-nav {
    display: none;
  }
}

/* ===========================================
   6. LOADING STATES
   =========================================== */

/* Button Loading Spinner */
.btn-loading {
  position: relative;
  color: transparent !important;
  pointer-events: none;
}

.btn-loading::after {
  content: '';
  position: absolute;
  width: 20px;
  height: 20px;
  top: 50%;
  left: 50%;
  margin: -10px 0 0 -10px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Skeleton Loading */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-cream) 25%,
    var(--color-beige) 50%,
    var(--color-cream) 75%
  );
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s infinite;
  border-radius: var(--radius-md);
}

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

.skeleton-text {
  height: 1em;
  margin-bottom: var(--space-2);
}

.skeleton-title {
  height: 1.5em;
  width: 60%;
  margin-bottom: var(--space-4);
}

.skeleton-avatar {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
}

.skeleton-card {
  height: 200px;
}

/* Page Loading Overlay */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: var(--z-modal);
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.9);
}

.loading-spinner {
  width: 48px;
  height: 48px;
  border: 3px solid var(--color-beige);
  border-top-color: var(--color-bleu-electrique);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

/* ===========================================
   7. TOAST NOTIFICATIONS
   =========================================== */

.toast-container {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-width: 400px;
}

.toast {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-4);
  background: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  animation: toast-in var(--transition-slow);
}

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

.toast-success {
  border-left: 4px solid var(--color-success);
}

.toast-error {
  border-left: 4px solid var(--color-error);
}

.toast-warning {
  border-left: 4px solid var(--color-warning);
}

.toast-info {
  border-left: 4px solid var(--color-info);
}

.toast-icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
}

.toast-content {
  flex: 1;
}

.toast-title {
  font-weight: 600;
  color: var(--color-charcoal);
  margin-bottom: var(--space-1);
}

.toast-message {
  font-size: var(--text-sm);
  color: var(--color-gray-dark);
}

.toast-close {
  flex-shrink: 0;
  padding: var(--space-1);
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--color-gray-medium);
  transition: color var(--transition-fast);
}

.toast-close:hover {
  color: var(--color-charcoal);
}

/* ===========================================
   8. ALERT COMPONENTS
   =========================================== */

.alert {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-4);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
}

.alert-icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
}

.alert-success {
  background: var(--color-success-light);
  color: #065f46;
}

.alert-error {
  background: var(--color-error-light);
  color: #991b1b;
}

.alert-warning {
  background: var(--color-warning-light);
  color: #92400e;
}

.alert-info {
  background: var(--color-info-light);
  color: #1e40af;
}

/* ===========================================
   9. ACCORDION (FAQ) COMPONENT
   =========================================== */

.accordion {
  border-radius: var(--radius-xl);
  overflow: hidden;
}

.accordion-item {
  border-bottom: 1px solid var(--color-beige);
}

.accordion-item:last-child {
  border-bottom: none;
}

.accordion-trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  min-height: var(--touch-target-min);
  padding: var(--space-5) var(--space-6);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 500;
  text-align: left;
  color: var(--color-charcoal);
  background: transparent;
  border: none;
  cursor: pointer;
  transition: background var(--transition-fast);
}

.accordion-trigger:hover {
  background: var(--color-cream);
}

.accordion-trigger[aria-expanded="true"] {
  background: var(--color-cream);
}

.accordion-icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  transition: transform var(--transition-base);
}

.accordion-trigger[aria-expanded="true"] .accordion-icon {
  transform: rotate(180deg);
}

.accordion-content {
  display: none;
  padding: 0 var(--space-6) var(--space-5);
  color: var(--color-gray-dark);
  line-height: var(--leading-relaxed);
}

.accordion-content[aria-hidden="false"],
.accordion-item.is-open .accordion-content {
  display: block;
}

/* ===========================================
   10. CARD COMPONENT
   =========================================== */

.card {
  background: var(--color-white);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card-body {
  padding: var(--space-6);
}

.card-header {
  padding: var(--space-6);
  border-bottom: 1px solid var(--color-beige);
}

.card-footer {
  padding: var(--space-4) var(--space-6);
  background: var(--color-cream);
}

/* ===========================================
   11. PASSWORD STRENGTH INDICATOR
   =========================================== */

.password-strength {
  margin-top: var(--space-3);
}

.password-strength-bars {
  display: flex;
  gap: var(--space-2);
  margin-bottom: var(--space-2);
}

.password-strength-bar {
  flex: 1;
  height: 4px;
  background: var(--color-beige);
  border-radius: var(--radius-full);
  transition: background var(--transition-fast);
}

.password-strength[data-strength="weak"] .password-strength-bar:nth-child(1) {
  background: var(--color-error);
}

.password-strength[data-strength="medium"] .password-strength-bar:nth-child(1),
.password-strength[data-strength="medium"] .password-strength-bar:nth-child(2) {
  background: var(--color-warning);
}

.password-strength[data-strength="strong"] .password-strength-bar {
  background: var(--color-success);
}

.password-strength-label {
  font-size: var(--text-xs);
  color: var(--color-gray-medium);
}

.password-strength-criteria {
  margin-top: var(--space-3);
  font-size: var(--text-xs);
  color: var(--color-gray-medium);
}

.password-strength-criteria li {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-1);
}

.password-strength-criteria li.is-valid {
  color: var(--color-success);
}

/* ===========================================
   12. UTILITY CLASSES
   =========================================== */

/* Visually Hidden (for accessibility) */
.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

/* Text Alignment */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

/* Flex Utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }

/* Spacing Utilities */
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }

/* Color Utilities */
.text-error { color: var(--color-error); }
.text-success { color: var(--color-success); }
.text-muted { color: var(--color-gray-medium); }

/* ===========================================
   13. RESPONSIVE UTILITIES
   =========================================== */

@media (max-width: 768px) {
  .hide-mobile { display: none !important; }

  .toast-container {
    left: var(--space-4);
    right: var(--space-4);
    max-width: none;
  }
}

@media (min-width: 769px) {
  .hide-desktop { display: none !important; }
}