/* CSS Custom Properties (Variables) */
:root {
  /* Light Theme Colors */
  --primary-50: #f0f9ff;
  --primary-100: #e0f2fe;
  --primary-200: #bae6fd;
  --primary-300: #7dd3fc;
  --primary-400: #38bdf8;
  --primary-500: #0ea5e9;
  --primary-600: #0284c7;
  --primary-700: #0369a1;
  --primary-800: #075985;
  --primary-900: #0c4a6e;

  --secondary-50: #fdf4ff;
  --secondary-100: #fae8ff;
  --secondary-200: #f5d0fe;
  --secondary-300: #f0abfc;
  --secondary-400: #e879f9;
  --secondary-500: #d946ef;
  --secondary-600: #c026d3;
  --secondary-700: #a21caf;
  --secondary-800: #86198f;
  --secondary-900: #701a75;

  --success-500: #10b981;
  --warning-500: #f59e0b;
  --error-500: #ef4444;

  /* Neutral Colors */
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;

  /* Theme Variables */
  --bg-primary: #ffffff;
  --bg-secondary: var(--gray-50);
  --bg-tertiary: var(--gray-100);
  --text-primary: var(--gray-900);
  --text-secondary: var(--gray-600);
  --text-tertiary: var(--gray-400);
  --border-color: var(--gray-200);
  --border-color-light: var(--gray-100);
  --shadow-color: rgba(0, 0, 0, 0.1);
  --shadow-color-strong: rgba(0, 0, 0, 0.15);

  /* Typography */
  --font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    sans-serif;
  --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 */
  --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;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1),
    0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1),
    0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1),
    0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 300ms ease-in-out;
  --transition-slow: 500ms ease-in-out;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background: linear-gradient(
    135deg,
    var(--bg-primary) 0%,
    var(--bg-secondary) 100%
  );
  color: var(--text-primary);
  line-height: 1.6;
  font-size: var(--font-size-base);
  min-height: 100vh;
  overflow-x: hidden;
  transition: background var(--transition-normal),
    color var(--transition-normal);
}

/* Header */
.header {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color-light);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: all var(--transition-normal);
}

.header-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--space-4) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.logo i {
  font-size: var(--font-size-2xl);
  color: var(--primary-600);
  animation: pulse 2s infinite;
}

.logo h1 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary-600), var(--secondary-600));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-item {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  font-weight: 500;
}

/* Main Content */
.main {
  min-height: calc(100vh - 140px);
  padding: var(--space-8) 0;
}

.app-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* Hero Section */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
  align-items: center;
  margin-bottom: var(--space-6);
  animation: fadeInUp 0.8s ease-out;
}

.hero-content {
  text-align: left;
}

.hero-title {
  font-size: var(--font-size-4xl);
  font-weight: 700;
  margin-bottom: var(--space-4);
  background: linear-gradient(
    135deg,
    var(--text-primary),
    var(--text-secondary)
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  line-height: 1.7;
}

/* Control Panel */
.control-panel {
  margin-bottom: var(--space-6);
  animation: fadeInUp 0.8s ease-out 0.2s both;
  justify-self: end;
}

/* Responsive: Stack on smaller screens */
@media (max-width: 768px) {
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--space-6);
  }

  .hero-content {
    text-align: center;
  }

  .control-panel {
    justify-self: center;
  }
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
  align-items: center;
}

.file-upload-wrapper {
  position: relative;
}

.file-input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.file-upload-label {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-6);
  background: var(--bg-primary);
  border: 2px dashed var(--border-color);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-weight: 500;
  box-shadow: var(--shadow-sm);
}

.file-upload-label:hover {
  border-color: var(--primary-400);
  background: var(--primary-50);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.action-buttons {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  justify-content: center;
}

/* Buttons */
.btn {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border: none;
  border-radius: var(--radius-lg);
  font-family: inherit;
  font-size: var(--font-size-base);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.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-normal);
}

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

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

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

.btn-primary {
  background: linear-gradient(135deg, var(--primary-600), var(--primary-500));
  color: white;
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-700), var(--primary-600));
}

.btn-secondary {
  background: linear-gradient(
    135deg,
    var(--secondary-600),
    var(--secondary-500)
  );
  color: white;
}

.btn-secondary:hover {
  background: linear-gradient(
    135deg,
    var(--secondary-700),
    var(--secondary-600)
  );
}

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

.btn-outline:hover {
  border-color: var(--primary-400);
  background: var(--primary-50);
}

/* Visualization Section */
.visualization {
  margin-bottom: var(--space-12);
}

.panels-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
  gap: var(--space-8);
  animation: fadeInUp 0.8s ease-out 0.4s both;
}

.panel {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(20px);
  border: 1px solid var(--border-color-light);
  border-radius: var(--radius-2xl);
  padding: var(--space-6);
  box-shadow: var(--shadow-xl);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-500), var(--secondary-500));
  border-radius: var(--radius-2xl) var(--radius-2xl) 0 0;
}

.panel:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-2xl);
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-6);
}

.panel-title {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--text-primary);
}

.panel-title i {
  color: var(--primary-600);
}

.panel-info,
.panel-status {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.tooltip {
  position: relative;
  cursor: help;
  color: var(--text-tertiary);
  transition: color var(--transition-fast);
}

.tooltip:hover {
  color: var(--primary-600);
}

.tooltip::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: 125%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gray-800);
  color: white;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  font-size: var(--font-size-xs);
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-fast);
  z-index: 10;
}

.tooltip:hover::after {
  opacity: 1;
  visibility: visible;
}

.status-indicator {
  padding: var(--space-1) var(--space-3);
  background: var(--success-500);
  color: white;
  border-radius: var(--radius-md);
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Canvas Container */
.canvas-container {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  padding: var(--space-4);
  box-shadow: inset 0 2px 4px var(--shadow-color);
}

canvas {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-fast);
}

canvas:hover {
  box-shadow: var(--shadow-lg);
}

.canvas-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.1);
  opacity: 1;
  visibility: visible;
  transition: opacity var(--transition-fast), visibility var(--transition-fast);
  border-radius: var(--radius-xl);
  pointer-events: none; /* Allow clicks to pass through to canvas by default */
}

/* Special styling for input panel overlay to allow drawing through instructions */
.input-panel .canvas-overlay {
  pointer-events: none;
}

.input-panel .canvas-overlay .instructions {
  pointer-events: none;
}

/* Instructions are controlled by JavaScript, not hover */

.instructions {
  background: rgba(0, 0, 0, 0.8);
  color: white;
  padding: var(--space-4);
  border-radius: var(--radius-lg);
  text-align: center;
  pointer-events: none; /* Allow clicks to pass through to canvas */
}

.instructions p {
  font-size: var(--font-size-sm);
  margin-bottom: var(--space-1);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
}

.instructions p:last-child {
  margin-bottom: 0;
}

.processing-indicator {
  display: none;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  background: rgba(0, 0, 0, 0.9);
  color: white;
  padding: var(--space-6);
  border-radius: var(--radius-lg);
}

.processing-indicator.active {
  display: flex;
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-top: 3px solid white;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

/* Statistics Panel */
.stats-panel {
  animation: fadeInUp 0.8s ease-out 0.6s both;
}

.stats-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-4);
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(20px);
  border: 1px solid var(--border-color-light);
  border-radius: var(--radius-2xl);
  padding: var(--space-6);
  box-shadow: var(--shadow-lg);
}

.stat-item {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4);
  background: var(--bg-primary);
  border-radius: var(--radius-lg);
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.stat-item:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.stat-item i {
  font-size: var(--font-size-xl);
  color: var(--primary-600);
  width: 24px;
  text-align: center;
}

.stat-info {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.stat-value {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--text-primary);
}

/* Footer */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  margin-top: auto;
}

.footer-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--space-6);
}

.footer-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
  color: var(--text-primary);
}

.footer-brand i {
  color: var(--primary-600);
}

.footer-info {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.separator {
  opacity: 0.5;
}

/* Loading Overlay */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  backdrop-filter: blur(5px);
}

.loading-overlay.active {
  display: flex;
}

.loading-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
  background: var(--bg-primary);
  padding: var(--space-8);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-2xl);
}

.loading-spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--border-color);
  border-top: 4px solid var(--primary-600);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

.loading-text {
  font-weight: 600;
  color: var(--text-primary);
}

/* Notifications */
.notification-container {
  position: fixed;
  top: var(--space-4);
  left: 50%;
  transform: translateX(-50%);
  z-index: 10000;
  pointer-events: none;
}

.notification {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-4) var(--space-6);
  margin-bottom: var(--space-3);
  box-shadow: var(--shadow-lg);
  animation: slideInDown 0.3s ease-out;
  pointer-events: auto;
  max-width: 400px;
}

.notification.success {
  border-left: 4px solid var(--success-500);
}

.notification.error {
  border-left: 4px solid var(--error-500);
}

.notification.warning {
  border-left: 4px solid var(--warning-500);
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

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

@keyframes pulse {
  0%,
  100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.8;
    transform: scale(1.05);
  }
}

/* Responsive Design */
@media (max-width: 768px) {
  .header-container {
    padding: var(--space-3) var(--space-4);
  }

  .logo h1 {
    font-size: var(--font-size-xl);
  }

  .app-container {
    padding: 0 var(--space-4);
  }

  .hero-title {
    font-size: var(--font-size-3xl);
  }

  .panels-container {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }

  .panel {
    padding: var(--space-4);
  }

  .canvas-container {
    padding: var(--space-2);
  }

  canvas {
    width: 100%;
    height: auto;
    max-width: 350px;
    max-height: 350px;
  }

  .action-buttons {
    flex-direction: column;
    width: 100%;
  }

  .btn {
    justify-content: center;
    width: 100%;
  }

  .footer-content {
    flex-direction: column;
    text-align: center;
  }

  .stats-container {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-3);
    padding: var(--space-4);
  }

  .stat-item {
    padding: var(--space-3);
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: var(--font-size-2xl);
  }

  .stats-container {
    grid-template-columns: 1fr;
  }

  canvas {
    max-width: 280px;
    max-height: 280px;
  }
}