/**
 * Neural Network System - Modern Stylesheet
 * 
 * A beautiful, modern UI for the Multi-Layer Perceptron
 * digit recognition application.
 * 
 * Features:
 * - Modern gradient backgrounds
 * - Glass-morphism card effects
 * - Smooth animations and transitions
 * - Fully responsive design
 * - Beautiful color scheme
 * 
 * @author Akhil Sirvi
 */

/* =============================================================================
   CSS CUSTOM PROPERTIES (Variables)
   ============================================================================= */
:root {
  /* Color Palette */
  --primary-color: #6366f1;
  --primary-dark: #4f46e5;
  --primary-light: #818cf8;
  --accent-color: #f59e0b;
  --accent-dark: #d97706;
  --success-color: #10b981;
  --success-dark: #059669;
  --danger-color: #ef4444;
  
  /* Neutral Colors */
  --bg-dark: #0f172a;
  --bg-medium: #1e293b;
  --bg-light: #334155;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  /* Glass Effect */
  --glass-bg: rgba(255, 255, 255, 0.1);
  --glass-border: rgba(255, 255, 255, 0.2);
  --glass-shadow: rgba(0, 0, 0, 0.3);
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
  --transition-slow: 500ms ease;
}

/* =============================================================================
   GLOBAL RESET & BASE STYLES
   ============================================================================= */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: linear-gradient(135deg, var(--bg-dark) 0%, var(--bg-medium) 50%, var(--bg-dark) 100%);
  background-attachment: fixed;
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
  overflow-x: hidden;
}

.icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-style: normal;
  line-height: 1;
}

/* Animated background effect */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(ellipse at 20% 20%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 80%, rgba(245, 158, 11, 0.1) 0%, transparent 50%),
    radial-gradient(ellipse at 50% 50%, rgba(16, 185, 129, 0.05) 0%, transparent 70%);
  pointer-events: none;
  z-index: -1;
}

/* =============================================================================
   HEADER STYLES
   ============================================================================= */
.header {
  padding: var(--spacing-xl) var(--spacing-md);
  text-align: center;
  background: linear-gradient(180deg, rgba(99, 102, 241, 0.2) 0%, transparent 100%);
}

.header-content {
  max-width: 800px;
  margin: 0 auto;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--primary-light);
  margin-bottom: var(--spacing-md);
}

.logo .icon {
  font-size: 2rem;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.1); opacity: 0.8; }
}

.title {
  font-size: clamp(1.75rem, 5vw, 3rem);
  font-weight: 700;
  background-clip: text;
  margin-bottom: var(--spacing-sm);
}

.subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  font-weight: 300;
}

/* =============================================================================
   CARD COMPONENT
   ============================================================================= */
.card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  overflow: hidden;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.card-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg);
  background: rgba(255, 255, 255, 0.05);
  border-bottom: 1px solid var(--glass-border);
}

.card-header .icon {
  font-size: 1.25rem;
  color: var(--primary-light);
}

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

.card-body {
  padding: var(--spacing-lg);
}

/* =============================================================================
   MAIN APPLICATION LAYOUT
   ============================================================================= */
.main-app {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: auto auto;
  gap: var(--spacing-xl);
  max-width: 1000px;
  margin: 0 auto;
  padding: var(--spacing-xl);
}

.drawing-section {
  grid-column: 1;
  grid-row: 1;
}

.output-section {
  grid-column: 2;
  grid-row: 1;
}

.actions-section {
  grid-column: 1 / -1;
  grid-row: 2;
  display: flex;
  justify-content: center;
  gap: var(--spacing-lg);
  flex-wrap: wrap;
}

/* =============================================================================
   DRAWING GRID STYLES
   ============================================================================= */
.drawing-card .card-body {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-lg);
}

#second, .drawing-grid {
  display: grid;
  grid-template-columns: repeat(28, 1fr);
  gap: 1px;
  background: var(--bg-light);
  padding: 2px;
  border-radius: var(--radius-md);
  box-shadow: 
    inset 0 2px 10px rgba(0, 0, 0, 0.3),
    0 0 30px rgba(99, 102, 241, 0.2);
  cursor: crosshair;
}

.box {
  width: 12px;
  height: 12px;
  background-color: #ffffff;
  border-radius: 1px;
  transition: background-color var(--transition-fast), transform var(--transition-fast);
}

.box:hover {
  background-color: var(--primary-light) !important;
  transform: scale(1.1);
}

/* =============================================================================
   OUTPUT PANEL STYLES
   ============================================================================= */
#first, .output-card {
  height: 100%;
  min-height: 400px;
  width: auto;
  margin: 0;
  background: var(--glass-bg);
}

.output-card .card-body {
  height: calc(100% - 60px);
  display: flex;
  align-items: flex-start;
  justify-content: center;
}

#output_text, .prediction-output {
  width: 100%;
  height: 100%;
  font-size: 1rem;
  line-height: 1.8;
  overflow-y: auto;
  padding: var(--spacing-md);
}

.placeholder-text {
  color: var(--text-muted);
  text-align: center;
  font-style: italic;
}

/* =============================================================================
   BUTTON STYLES
   ============================================================================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  font-family: inherit;
  font-size: 1rem;
  font-weight: 500;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-decoration: none;
  white-space: nowrap;
}

.btn:active {
  transform: scale(0.98);
}

.btn-large {
  padding: var(--spacing-lg) var(--spacing-2xl);
  font-size: 1.1rem;
}

/* Primary Button */
.btn-primary {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
  color: white;
  box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary-color) 100%);
  box-shadow: 0 6px 25px rgba(99, 102, 241, 0.5);
  transform: translateY(-2px);
}

/* Accent Button */
.btn-accent {
  background: linear-gradient(135deg, var(--accent-color) 0%, var(--accent-dark) 100%);
  color: white;
  box-shadow: 0 4px 15px rgba(245, 158, 11, 0.4);
}

.btn-accent:hover {
  background: linear-gradient(135deg, #fbbf24 0%, var(--accent-color) 100%);
  box-shadow: 0 6px 25px rgba(245, 158, 11, 0.5);
  transform: translateY(-2px);
}

/* Success Button */
.btn-success {
  background: linear-gradient(135deg, var(--success-color) 0%, var(--success-dark) 100%);
  color: white;
  box-shadow: 0 4px 15px rgba(16, 185, 129, 0.4);
}

.btn-success:hover {
  background: linear-gradient(135deg, #34d399 0%, var(--success-color) 100%);
  box-shadow: 0 6px 25px rgba(16, 185, 129, 0.5);
  transform: translateY(-2px);
}

/* Secondary Button */
.btn-secondary {
  background: var(--glass-bg);
  color: var(--text-primary);
  border: 1px solid var(--glass-border);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.2);
}

.btn-clear {
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: 0.9rem;
}

/* Legacy button support */
#enterdatabutton, #traindatabutton {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg) var(--spacing-2xl);
  font-family: inherit;
  font-size: 1.1rem;
  font-weight: 500;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-normal);
}

/* =============================================================================
   CONTROLS SECTION
   ============================================================================= */
.controls-section {
  max-width: 1000px;
  margin: var(--spacing-xl) auto;
  padding: 0 var(--spacing-xl);
}

.controls-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-lg);
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.control-group label {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.control-group label .icon {
  color: var(--primary-light);
  width: 16px;
}

.control-group input[type="number"],
.control-group input[type="text"] {
  padding: var(--spacing-md);
  font-family: inherit;
  font-size: 1rem;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  transition: all var(--transition-normal);
}

.control-group input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.control-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.control-button {
  justify-content: flex-end;
}

/* Metrics Display */
#cost_value_output, .metrics-display {
  margin-top: var(--spacing-lg);
  padding: var(--spacing-lg);
  background: rgba(0, 0, 0, 0.2);
  border-radius: var(--radius-md);
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--success-color);
}

#cost_value_output:empty, .metrics-display:empty {
  display: none;
}

/* =============================================================================
   PROGRESS MODAL
   ============================================================================= */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.8);
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 1000;
}

#loadbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.8);
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 1000;
  flex-direction: column;
}

.modal-content {
  background: var(--bg-medium);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-2xl);
  width: 90%;
  max-width: 450px;
  text-align: center;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-xl);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--primary-light);
}

.progress-container {
  width: 100%;
  height: 12px;
  background: var(--bg-dark);
  border-radius: 6px;
  overflow: hidden;
  margin-bottom: var(--spacing-lg);
}

#loadbarmain, .progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color), var(--success-color));
  border-radius: 6px;
  transition: width var(--transition-normal);
  animation: shimmer 2s ease-in-out infinite;
}

#loadbartitle {
  color: var(--primary-light);
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-lg);
}

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

.progress-text {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* =============================================================================
   CHART SECTION
   ============================================================================= */
.chart-section {
  max-width: 1000px;
  margin: var(--spacing-xl) auto;
  padding: 0 var(--spacing-xl);
}

.chart-card .card-body {
  padding: var(--spacing-xl);
}

#graphcanvas {
  width: 100% !important;
  height: auto !important;
  max-height: 400px;
  max-width: 100%;
  margin: var(--spacing-xl) auto;
  display: block;
}

/* =============================================================================
   FOOTER
   ============================================================================= */
.footer {
  margin-top: var(--spacing-2xl);
  padding: var(--spacing-xl);
  text-align: center;
  border-top: 1px solid var(--glass-border);
  background: rgba(0, 0, 0, 0.2);
}

.footer-content {
  max-width: 800px;
  margin: 0 auto;
}

.footer p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
}

.footer .heart-icon {
  color: var(--danger-color);
}

@keyframes heartbeat {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.2); }
}

.footer-links a {
  color: var(--primary-light);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  transition: color var(--transition-normal);
}

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

/* =============================================================================
   RESPONSIVE DESIGN
   ============================================================================= */

/* Tablet and below */
@media only screen and (max-width: 834px) {
  .main-app {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
    padding: var(--spacing-md);
  }

  .drawing-section,
  .output-section {
    grid-column: 1;
  }

  .drawing-section {
    grid-row: 1;
  }

  .output-section {
    grid-row: 2;
  }

  .actions-section {
    grid-row: 3;
    flex-direction: column;
    align-items: stretch;
  }

  .btn-large,
  #enterdatabutton,
  #traindatabutton {
    width: 100%;
  }

  .controls-section,
  .chart-section {
    padding: 0 var(--spacing-md);
  }

  .controls-grid {
    grid-template-columns: 1fr;
  }
}

/* Mobile */
@media only screen and (max-width: 480px) {
  :root {
    --spacing-xl: 1.5rem;
    --spacing-2xl: 2rem;
  }

  .header {
    padding: var(--spacing-lg) var(--spacing-md);
  }

  .logo {
    font-size: 1.25rem;
  }

  .logo .icon {
    font-size: 1.5rem;
  }

  .box {
    width: 11px;
    height: 11px;
  }

  #second, .drawing-grid {
    gap: 0;
  }

  .card-header {
    padding: var(--spacing-md);
  }

  .card-body {
    padding: var(--spacing-md);
  }

  .btn {
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 0.9rem;
  }

  .btn-large,
  #enterdatabutton,
  #traindatabutton {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1rem;
  }
}

/* Very small screens */
@media only screen and (max-width: 360px) {
  .box {
    width: 9px;
    height: 9px;
  }
}

/* =============================================================================
   UTILITY CLASSES
   ============================================================================= */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

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

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

/* =============================================================================
   SCROLLBAR STYLING
   ============================================================================= */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--bg-light);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-color);
}

/* =============================================================================
   SELECTION STYLING
   ============================================================================= */
::selection {
  background: var(--primary-color);
  color: white;
}

::-moz-selection {
  background: var(--primary-color);
  color: white;
}

/* =============================================================================
   TOGGLE SWITCH STYLES
   ============================================================================= */
.toggle-container {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.toggle-switch {
  position: relative;
  display: inline-block;
  width: 50px;
  height: 26px;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--bg-light);
  transition: var(--transition-normal);
  border-radius: 26px;
  border: 1px solid var(--glass-border);
}

.toggle-slider:before {
  position: absolute;
  content: "";
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background-color: var(--text-muted);
  transition: var(--transition-normal);
  border-radius: 50%;
}

.toggle-switch input:checked + .toggle-slider {
  background: linear-gradient(135deg, var(--success-color) 0%, var(--success-dark) 100%);
  border-color: var(--success-color);
}

.toggle-switch input:checked + .toggle-slider:before {
  transform: translateX(24px);
  background-color: white;
}

.toggle-switch input:focus + .toggle-slider {
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.3);
}

.toggle-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  min-width: 60px;
}

.toggle-label.active {
  color: var(--success-color);
}

/* =============================================================================
   CHART CONTROLS STYLES
   ============================================================================= */
.chart-card .card-header {
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.chart-controls {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-left: auto;
  flex-wrap: wrap;
}

.chart-controls-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.btn-group {
  display: flex;
  gap: 2px;
  background: rgba(0, 0, 0, 0.3);
  padding: 3px;
  border-radius: var(--radius-md);
}

.btn-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-sm);
  font-family: inherit;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.btn-chip:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.1);
}

.btn-chip.active {
  color: var(--text-primary);
  background: #000000;
  box-shadow: 0 2px 8px rgba(99, 102, 241, 0.4);
}

.btn-chip-icon {
  padding: var(--spacing-xs) var(--spacing-sm);
  background: rgba(0, 0, 0, 0.3);
  border-radius: var(--radius-md);
}

.btn-chip-icon.active {
  background: var(--primary-color);
}

.btn-chip .icon {
  font-size: 0.7rem;
}

.spin {
  animation: spin 1.6s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@media only screen and (max-width: 834px) {
  .chart-controls {
    width: 100%;
    justify-content: flex-start;
    margin-left: 0;
    margin-top: var(--spacing-sm);
  }
  
  .chart-card .card-header h2 {
    flex: 1;
  }
}