/* --- Design System & CSS Variables --- */
:root {
  --font-sans: 'Plus Jakarta Sans', system-ui, sans-serif;
  --font-mono: 'Fira Code', monospace;
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  
  --transition-fast: 0.15s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 10px 35px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 20px 50px rgba(0, 0, 0, 0.15);
}

/* --- Dark Theme Variables --- */
body.dark-theme {
  --bg-app: #050609;
  --bg-panel: #0b0c11;
  --bg-card: rgba(18, 20, 29, 0.6);
  --bg-card-hover: rgba(25, 28, 41, 0.85);
  --bg-input: #12141f;
  --border-color: rgba(255, 255, 255, 0.07);
  --border-hover: rgba(255, 255, 255, 0.15);
  
  --text-primary: #eff1f5;
  --text-secondary: #9aa0b2;
  --text-muted: #5e6375;
  
  --accent-color: #3b82f6;
  --accent-color-hover: #2563eb;
  --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #a855f7 50%, #ec4899 100%);
  --accent-glow: rgba(59, 130, 246, 0.25);
  
  --toast-bg: rgba(11, 12, 17, 0.95);
  --toast-border: rgba(99, 102, 241, 0.3);
  --color-success: #10b981;
  --color-warning: #f59e0b;
}

/* --- Light Theme Variables --- */
body.light-theme {
  --bg-app: #f0f2f5;
  --bg-panel: #ffffff;
  --bg-card: rgba(239, 241, 244, 0.8);
  --bg-card-hover: rgba(239, 241, 244, 1);
  --bg-input: #ffffff;
  --border-color: rgba(0, 0, 0, 0.08);
  --border-hover: rgba(0, 0, 0, 0.15);
  
  --text-primary: #1f2937;
  --text-secondary: #4b5563;
  --text-muted: #9ca3af;
  
  --accent-color: #2563eb;
  --accent-color-hover: #1d4ed8;
  --accent-gradient: linear-gradient(135deg, #2563eb 0%, #7c3aed 50%, #db2777 100%);
  --accent-glow: rgba(37, 99, 235, 0.15);
  
  --toast-bg: rgba(255, 255, 255, 0.95);
  --toast-border: rgba(37, 99, 235, 0.2);
  --color-success: #059669;
  --color-warning: #d97706;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-app);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  overflow-x: hidden;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-app);
}

::-webkit-scrollbar-thumb {
  background: var(--text-muted);
  border-radius: 99px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}

/* --- Layout Container --- */
.app-container {
  width: 100%;
  max-width: 1540px;
  margin: 0 auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  flex-grow: 1;
}

/* --- Header --- */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-icon-wrapper {
  background: var(--accent-gradient);
  color: white;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 14px var(--accent-glow);
}

.logo-icon {
  width: 20px;
  height: 20px;
}

.header-logo h1 {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 0.8rem;
}

.header-actions {
  display: flex;
  align-items: center;
}

/* Theme Button */
.theme-toggle-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  background: var(--bg-card-hover);
  transform: translateY(-1px);
}

body.dark-theme .sun-icon,
body.light-theme .moon-icon {
  display: block;
}

body.dark-theme .moon-icon,
body.light-theme .sun-icon {
  display: none;
}

.theme-toggle-btn svg {
  width: 18px;
  height: 18px;
}

/* --- Main Workspace Layout --- */
.app-main {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  flex-grow: 1;
  min-height: 0;
  height: calc(100vh - 120px);
}

@media (max-width: 1024px) {
  .app-main {
    grid-template-columns: 1fr;
    height: auto;
  }
}

.panel {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  height: 100%;
  min-height: 0;
  overflow-y: auto;
  padding-right: 4px;
}

/* --- Card Styles --- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  backdrop-filter: blur(10px);
}

.card-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-color);
}

.card-header svg {
  color: var(--accent-color);
  width: 20px;
  height: 20px;
}

.card-header h2 {
  font-size: 1.1rem;
  font-weight: 600;
}

.controls-grid {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* Inputs Form Elements */
.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.input-group label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.input-group input[type="text"] {
  font-family: var(--font-sans);
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.65rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  outline: none;
  transition: all var(--transition-fast);
}

.input-group input[type="text"]:focus {
  border-color: var(--accent-color);
}

.custom-select {
  font-family: var(--font-sans);
  background-color: var(--bg-input);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.65rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  outline: none;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.custom-select:hover {
  border-color: var(--border-hover);
}

/* --- Color Picker Styling --- */
.color-picker-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.color-picker-wrapper {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 4px 8px;
}

.color-picker-wrapper input[type="color"] {
  -webkit-appearance: none;
  appearance: none;
  border: none;
  width: 24px;
  height: 24px;
  border-radius: 4px;
  cursor: pointer;
  background: none;
  padding: 0;
}

.color-picker-wrapper input[type="color"]::-webkit-color-swatch-wrapper {
  padding: 0;
}

.color-picker-wrapper input[type="color"]::-webkit-color-swatch {
  border: 1px solid var(--border-color);
  border-radius: 4px;
}

.hex-label {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-primary);
}

/* --- File Uploading Styling --- */
.file-upload-wrapper {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 4px 8px;
}

.hidden-file-input {
  display: none;
}

.file-name-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex-grow: 1;
}

.btn-clear {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
}

.btn-clear:hover {
  color: #ef4444;
}

/* --- Range Slider Slider --- */
.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.control-group label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.badge {
  background: var(--accent-color);
  color: white;
  padding: 1px 6px;
  border-radius: 99px;
  font-size: 0.7rem;
  font-weight: 700;
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  border-radius: 99px;
  background: var(--bg-input);
  outline: none;
  border: 1px solid var(--border-color);
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent-color);
  cursor: pointer;
  border: 2px solid #fff;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

/* Checkbox Style */
.checkbox-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
}

.checkbox-group input {
  accent-color: var(--accent-color);
  cursor: pointer;
  width: 15px;
  height: 15px;
}

.checkbox-group label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
}

/* --- Buttons --- */
.btn {
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 0.875rem;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  transition: all var(--transition-fast);
}

.btn-sm {
  padding: 0.4rem 0.85rem;
  font-size: 0.75rem;
  border-radius: 6px;
}

.btn-primary {
  background: var(--accent-gradient);
  color: white;
  box-shadow: 0 4px 12px var(--accent-glow);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px var(--accent-glow);
  filter: brightness(1.05);
}

.btn-secondary {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
}

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

/* --- Right Column: Preview --- */
.preview-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.reliability-badge {
  background-color: rgba(16, 185, 129, 0.15);
  color: var(--color-success);
  padding: 3px 8px;
  border-radius: 99px;
  font-size: 0.7rem;
  display: inline-flex;
  align-items: center;
  gap: 3px;
}

.reliability-badge.warn {
  background-color: rgba(245, 158, 11, 0.15);
  color: var(--color-warning);
}

.preview-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  min-height: 300px;
}

#qr-preview-container {
  background: #ffffff;
  padding: 1rem;
  border-radius: var(--radius-md);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  max-width: 100%;
}

#qr-preview-container canvas {
  max-width: 100%;
  height: auto !important;
  display: block;
}

/* Export Grid Layout */
.export-card {
  gap: 1rem;
}

.export-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 1rem;
}

@media (max-width: 640px) {
  .export-grid {
    grid-template-columns: 1fr;
  }
}

/* Diagnostic Checklist panel */
.reliability-checklist {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1rem;
}

.reliability-checklist h3 {
  font-size: 0.8rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.reliability-checklist ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.reliability-checklist li {
  font-size: 0.75rem;
  color: var(--text-secondary);
  display: flex;
  align-items: start;
  gap: 0.4rem;
  line-height: 1.4;
}

.reliability-checklist li svg {
  flex-shrink: 0;
  width: 14px;
  height: 14px;
  margin-top: 1px;
}

.check-icon { color: var(--color-success); }
.warn-icon { color: var(--color-warning); }

/* --- Toast Alerts --- */
.toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  z-index: 9999;
}

.toast {
  background: var(--toast-bg);
  border: 1px solid var(--toast-border);
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1.25rem;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  transform: translateY(20px);
  opacity: 0;
  animation: toast-in 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  backdrop-filter: blur(10px);
}

.toast svg {
  color: var(--color-success);
  width: 16px;
  height: 16px;
}

.toast-message {
  font-size: 0.85rem;
  font-weight: 500;
}

@keyframes toast-in {
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.toast.fade-out {
  animation: toast-out 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes toast-out {
  to {
    transform: translateY(10px);
    opacity: 0;
  }
}

/* Utility classes */
.hidden {
  display: none !important;
}