/* ===================================
   TranslAItion Design System
   ================================== */

/* CSS Custom Properties (Design Tokens) */
:root {
  /* Colors */
  --color-primary: #10b981;
  --color-primary-dark: #047857;
  --color-primary-darker: #065f46;
  --color-text: #e0e6ed;
  --color-text-muted: #9ca3af;
  --color-background: #0d0d0d;
  --color-surface: rgba(255, 255, 255, 0.03);
  --color-border: rgba(16, 185, 129, 0.3);
  --color-error: #ef4444;
  --color-warning: #f59e0b;
  --color-success: #10b981;
  
  /* Typography */
  --font-primary: 'Exo 2', sans-serif;
  --font-display: 'Orbitron', monospace;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  /* Borders */
  --border-radius-sm: 6px;
  --border-radius-md: 12px;
  --border-radius-lg: 20px;
  --border-radius-full: 50px;
  
  /* Shadows */
  --shadow-sm: 0 4px 15px rgba(16, 185, 129, 0.1);
  --shadow-md: 0 8px 32px rgba(16, 185, 129, 0.1);
  --shadow-lg: 0 20px 60px rgba(16, 185, 129, 0.2);
  --shadow-glow: 0 0 40px rgba(16, 185, 129, 0.2);
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.6s ease;
}

/* ===================================
   Base Styles
   ================================== */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-background);
  overflow-x: hidden;
}

/* Accessibility improvements */
@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;
  }
}

/* Focus styles for keyboard navigation */
*:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--border-radius-sm);
}

/* Skip link for accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: 6px;
  background: var(--color-primary);
  color: white;
  padding: 8px;
  text-decoration: none;
  border-radius: var(--border-radius-sm);
  z-index: 1000;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 6px;
}

/* ===================================
   Typography
   ================================== */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-text);
}

.text-display {
  font-family: var(--font-display);
  font-size: var(--font-size-4xl);
  font-weight: 900;
  text-shadow: 0 2px 20px rgba(16, 185, 129, 0.3);
}

.text-muted {
  color: var(--color-text-muted);
}

.text-primary {
  color: var(--color-primary);
}

/* ===================================
   Layout Components
   ================================== */

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.main-interface {
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 800px;
  margin: 0 auto;
  padding: var(--spacing-lg) var(--spacing-lg) 120px var(--spacing-lg);
  position: relative;
}

/* ===================================
   Button System
   ================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  border: none;
  border-radius: var(--border-radius-full);
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  font-weight: 600;
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 1px;
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  min-height: 48px; /* Touch target */
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left var(--transition-slow);
}

.btn:hover::before {
  left: 100%;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  pointer-events: none;
}

/* Button variants */
.btn--primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: white;
  box-shadow: var(--shadow-md);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.btn--secondary {
  background: linear-gradient(135deg, #6b7280, #4b5563);
  color: white;
  box-shadow: 0 8px 25px rgba(107, 114, 128, 0.3);
}

.btn--secondary:hover {
  box-shadow: 0 12px 35px rgba(107, 114, 128, 0.4);
}

.btn--floating {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1000;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.btn--floating:hover {
  transform: translateX(-50%) translateY(-3px);
}

/* ===================================
   Card System
   ================================== */

.card {
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-xl);
  backdrop-filter: blur(20px);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
}

.card:hover {
  transform: translateY(-2px);
  border-color: rgba(16, 185, 129, 0.4);
  box-shadow: var(--shadow-lg);
}

.card--interactive {
  cursor: pointer;
}

.card--featured {
  border-color: rgba(16, 185, 129, 0.6);
  background: rgba(16, 185, 129, 0.05);
}

/* ===================================
   Form Controls
   ================================== */

.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-label {
  display: block;
  color: var(--color-primary);
  font-size: var(--font-size-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: var(--spacing-sm);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: var(--spacing-md) var(--spacing-lg);
  background: rgba(0, 0, 0, 0.6);
  border: 2px solid rgba(16, 185, 129, 0.3);
  border-radius: var(--border-radius-md);
  color: var(--color-text);
  font-size: var(--font-size-base);
  font-family: var(--font-primary);
  transition: all var(--transition-base);
  outline: none;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.2);
  background: rgba(0, 0, 0, 0.8);
  transform: translateY(-1px);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: rgba(224, 230, 237, 0.4);
  font-style: italic;
}

/* ===================================
   Stage Indicators
   ================================== */

.stage-indicator {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  padding: 0;
}

.stage-bar {
  width: 60px;
  height: 4px;
  background: rgba(156, 163, 175, 0.2);
  border-radius: 2px;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.stage-bar--active {
  background: var(--color-primary);
  box-shadow: 0 0 10px rgba(16, 185, 129, 0.4);
}

.stage-bar--completed {
  background: var(--color-primary);
}

.stage-bar--active::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.6), transparent);
  animation: shimmer 1.5s ease-in-out infinite;
}

@keyframes shimmer {
  0% { left: -100%; }
  100% { left: 100%; }
}

/* ===================================
   Navigation
   ================================== */

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) var(--spacing-xl);
  background: rgba(255, 255, 255, 0.02);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(16, 185, 129, 0.2);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  text-decoration: none;
  color: inherit;
  transition: opacity var(--transition-base);
}

.nav-brand:hover {
  opacity: 0.8;
}

.nav-logo {
  width: 40px;
  height: 40px;
  border-radius: var(--border-radius-sm);
}

.nav-title {
  font-family: var(--font-display);
  font-size: var(--font-size-xl);
  font-weight: 600;
}

.nav-title .greeny {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark), var(--color-primary-darker));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
  list-style: none;
}

.nav-link {
  color: var(--color-text);
  text-decoration: none;
  font-weight: 500;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-base);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transform: translateX(-50%);
  transition: width var(--transition-base);
}

.nav-link:hover {
  color: var(--color-primary);
}

.nav-link:hover::after {
  width: 100%;
}

/* ===================================
   Loading States
   ================================== */

.loading-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  transform: scaleX(0);
  transform-origin: left;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
}

.loading-bar.active {
  opacity: 1;
  visibility: visible;
  animation: loadingProgress 3s ease-out forwards;
}

@keyframes loadingProgress {
  0% { transform: scaleX(0); }
  50% { transform: scaleX(0.7); }
  100% { transform: scaleX(1); }
}

.loading-dots {
  display: inline-flex;
  gap: var(--spacing-sm);
}

.loading-dot {
  width: 12px;
  height: 12px;
  background: var(--color-primary);
  border-radius: 50%;
  animation: loadingPulse 1.5s ease-in-out infinite;
}

.loading-dot:nth-child(2) { animation-delay: 0.2s; }
.loading-dot:nth-child(3) { animation-delay: 0.4s; }

@keyframes loadingPulse {
  0%, 100% { transform: scale(0.8); opacity: 0.5; }
  50% { transform: scale(1.2); opacity: 1; }
}

/* ===================================
   Utility Classes
   ================================== */

.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;
}

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

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

/* ===================================
   Responsive Design
   ================================== */

@media (max-width: 576px) {
  :root {
    --font-size-4xl: 1.875rem;
    --font-size-3xl: 1.5rem;
  }
  
  .container {
    padding: 0 var(--spacing-md);
  }
  
  .main-interface {
    padding: var(--spacing-md) var(--spacing-md) 100px var(--spacing-md);
  }
  
  .btn--floating {
    bottom: 20px;
    font-size: var(--font-size-sm);
    padding: 15px 35px;
  }
  
  .navbar {
    padding: var(--spacing-sm) var(--spacing-md);
  }
  
  .nav-menu {
    gap: var(--spacing-md);
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none; /* Could implement mobile menu here */
  }
  
  .card {
    padding: var(--spacing-lg);
  }
}

@media (min-width: 992px) {
  .container {
    padding: 0 var(--spacing-xl);
  }
}

@media (min-width: 1200px) {
  .container {
    max-width: 1400px;
  }
}

/* ===================================
   Animation Library
   ================================== */

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

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

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

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

@keyframes bounceHorizontal {
  0%, 100% { transform: translateX(0); }
  50% { transform: translateX(10px); }
}

.animate-fade-in {
  animation: fadeIn 0.3s ease-out;
}

.animate-slide-in-right {
  animation: slideInFromRight 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

/* ===================================
   Dark Theme Enhancements
   ================================== */

.particle-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
  background: 
    radial-gradient(circle at 20% 30%, rgba(16, 185, 129, 0.05) 0%, transparent 40%),
    radial-gradient(circle at 80% 70%, rgba(4, 120, 87, 0.03) 0%, transparent 40%),
    radial-gradient(circle at 50% 50%, rgba(6, 95, 70, 0.02) 0%, transparent 50%);
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --color-border: rgba(16, 185, 129, 0.8);
    --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.5);
  }
  
  .card {
    border-width: 3px;
  }
  
  .btn {
    border: 2px solid rgba(255, 255, 255, 0.2);
  }
}