/* Import modern font */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

/* Design Tokens */
:root {
  /* Colors - Premium palette */
  --primary: hsl(262, 83%, 58%);
  --primary-dark: hsl(262, 83%, 48%);
  --primary-light: hsl(262, 83%, 68%);
  --secondary: hsl(195, 100%, 50%);
  --accent: hsl(340, 82%, 52%);
  
  /* Gradients */
  --gradient-primary: linear-gradient(135deg, hsl(262, 83%, 58%) 0%, hsl(195, 100%, 50%) 100%);
  --gradient-secondary: linear-gradient(135deg, hsl(340, 82%, 52%) 0%, hsl(262, 83%, 58%) 100%);
  --gradient-glass: linear-gradient(135deg, rgba(255, 255, 255, 0.1) 0%, rgba(255, 255, 255, 0.05) 100%);
  
  /* Dark theme colors */
  --bg-primary: hsl(230, 20%, 7%);
  --bg-secondary: hsl(230, 15%, 12%);
  --bg-tertiary: hsl(230, 15%, 18%);
  --text-primary: hsl(0, 0%, 98%);
  --text-secondary: hsl(0, 0%, 70%);
  --text-tertiary: hsl(0, 0%, 50%);
  
  /* Glass effect */
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-shadow: rgba(0, 0, 0, 0.3);
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  
  /* Border radius */
  --radius-sm: 0.5rem;
  --radius-md: 1rem;
  --radius-lg: 1.5rem;
  --radius-xl: 2rem;
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 300ms ease-in-out;
  --transition-slow: 500ms ease-in-out;
  
  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 20px rgba(136, 69, 255, 0.4);
}

/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
}

/* Animated background */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(circle at 20% 30%, rgba(136, 69, 255, 0.15) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(0, 176, 255, 0.15) 0%, transparent 50%),
    radial-gradient(circle at 50% 50%, rgba(236, 72, 153, 0.1) 0%, transparent 50%);
  pointer-events: none;
  z-index: 0;
  animation: backgroundPulse 15s ease-in-out infinite;
}

@keyframes backgroundPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-lg);
  position: relative;
  z-index: 1;
}

/* Header */
.header {
  text-align: center;
  padding: var(--spacing-xl) 0;
  margin-bottom: var(--spacing-xl);
}

.header h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: var(--spacing-sm);
  animation: fadeInDown 0.8s ease-out;
}

.header p {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

/* Main Content */
.main-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
  animation: fadeIn 0.8s ease-out 0.4s both;
}

@media (max-width: 968px) {
  .main-content {
    grid-template-columns: 1fr;
  }
}

/* Glass Card */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-normal);
}

.glass-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  border-color: rgba(136, 69, 255, 0.3);
}

.card-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

/* Form Elements */
.form-group {
  margin-bottom: var(--spacing-md);
}

.form-group label {
  display: block;
  font-weight: 500;
  margin-bottom: var(--spacing-xs);
  color: var(--text-secondary);
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.input-field {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--bg-secondary);
  border: 2px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 1rem;
  font-family: inherit;
  transition: all var(--transition-normal);
  outline: none;
}

.input-field:focus {
  border-color: var(--primary);
  background: var(--bg-tertiary);
  box-shadow: 0 0 0 4px rgba(136, 69, 255, 0.1);
}

.input-field::placeholder {
  color: var(--text-tertiary);
}

textarea.input-field {
  min-height: 120px;
  resize: vertical;
  font-family: inherit;
}

/* Color Picker Group */
.color-picker-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-md);
}

.color-input-wrapper {
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
}

input[type="color"] {
  width: 60px;
  height: 44px;
  border: 2px solid var(--glass-border);
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  cursor: pointer;
  transition: all var(--transition-normal);
}

input[type="color"]:hover {
  border-color: var(--primary);
  transform: scale(1.05);
}

/* Slider */
input[type="range"] {
  width: 100%;
  height: 6px;
  background: var(--bg-secondary);
  border-radius: 3px;
  outline: none;
  appearance: none;
  -webkit-appearance: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--gradient-primary);
  border-radius: 50%;
  cursor: pointer;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: var(--shadow-glow);
}

input[type="range"]::-moz-range-thumb {
  width: 20px;
  height: 20px;
  background: var(--gradient-primary);
  border-radius: 50%;
  cursor: pointer;
  border: none;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
}

input[type="range"]::-moz-range-thumb:hover {
  transform: scale(1.2);
  box-shadow: var(--shadow-glow);
}

.slider-value {
  display: inline-block;
  margin-left: var(--spacing-sm);
  font-weight: 600;
  color: var(--primary);
  min-width: 3ch;
}

/* Preset Buttons */
.presets-section {
  margin-bottom: var(--spacing-lg);
  padding: var(--spacing-md);
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
  border: 1px solid var(--glass-border);
}

.preset-buttons {
  display: flex;
  gap: var(--spacing-xs);
  flex-wrap: wrap;
}

.preset-btn {
  padding: var(--spacing-xs) var(--spacing-sm);
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  font-family: inherit;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.preset-btn:hover {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
  transform: translateY(-1px);
}

.preset-btn:active {
  transform: translateY(0);
}

/* Buttons */
.btn {
  gap: var(--spacing-xs);
}

.btn-content,
.btn-loader {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-lg);
  background: var(--gradient-primary);
  color: white;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

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

.btn:active {
  transform: translateY(0);
}

.btn-full {
  width: 100%;
  margin-top: var(--spacing-md);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 2px solid var(--glass-border);
}

.btn-secondary:hover {
  background: var(--bg-secondary);
  border-color: var(--primary);
}

/* QR Code Display */
.qr-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 400px;
}

#qr-container {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 300px;
  margin: var(--spacing-lg) 0;
  padding: var(--spacing-lg);
  background: white;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

#qr-container:hover {
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

#qr-container canvas {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
}

.empty-state {
  text-align: center;
  color: var(--text-tertiary);
  padding: var(--spacing-xl);
}

.empty-state svg {
  width: 80px;
  height: 80px;
  margin-bottom: var(--spacing-md);
  opacity: 0.3;
}

/* Download Buttons */
.download-buttons {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  width: 100%;
}

.download-buttons .btn {
  flex: 1;
  min-width: 150px;
}

/* Footer */
.footer {
  text-align: center;
  padding: var(--spacing-xl) 0;
  color: var(--text-tertiary);
  font-size: 0.875rem;
}

.footer a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer a:hover {
  color: var(--primary-light);
}

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

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

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

/* Spinner */
.spinner {
  display: inline-block;
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: white;
  animation: spin 0.6s linear infinite;
}

/* Keyboard hint */
.keyboard-hint kbd,
kbd {
  display: inline-block;
  padding: 0.125rem 0.375rem;
  font-family: 'Courier New', monospace;
  font-size: 0.75rem;
  color: var(--text-primary);
  background: var(--bg-tertiary);
  border: 1px solid var(--glass-border);
  border-radius: 0.25rem;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

/* Loading State */
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: white;
  animation: spin 0.8s linear infinite;
}

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

/* Floating particles decoration */
.particle {
  position: fixed;
  background: var(--gradient-primary);
  border-radius: 50%;
  pointer-events: none;
  opacity: 0.1;
  animation: float 20s infinite;
  z-index: 0;
}

@keyframes float {
  0%, 100% {
    transform: translate(0, 0) rotate(0deg);
  }
  33% {
    transform: translate(30px, -30px) rotate(120deg);
  }
  66% {
    transform: translate(-20px, 20px) rotate(240deg);
  }
}

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: var(--spacing-md);
  }

  .preset-buttons {
    justify-content: center;
  }

  .preset-btn {
    flex: 1;
    min-width: calc(50% - var(--spacing-xs));
  }
  
  .header {
    padding: var(--spacing-lg) 0;
    margin-bottom: var(--spacing-lg);
  }
  
  .glass-card {
    padding: var(--spacing-lg);
  }
  
  .color-picker-group {
    grid-template-columns: 1fr;
  }
  
  .download-buttons {
    flex-direction: column;
  }
  
  .download-buttons .btn {
    width: 100%;
  }
}

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

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