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

:root {
  --primary: #5c6bc0;
  --primary-dark: #3949ab;
  --accent: #ff7043;
  --success: #66bb6a;
  --danger: #ef5350;
  --text-primary: #2c3e50;
  --text-secondary: #607d8b;
  --bg-light: #f5f7fa;
  --border: #e0e4e8;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.12);
  --type-a-color: #3f51b5;
  --type-b-color: #ff9800;
  --empty-color: #eceff1;
  --moved-glow: #e040fb;
  --radius: 10px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, Cantarell, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background: linear-gradient(135deg, #1a237e 0%, #283593 50%, #3949ab 100%);
  min-height: 100vh;
  padding: 20px;
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  background: #fff;
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

/* Header */
header {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff;
  padding: 36px 30px;
  text-align: center;
}

header h1 {
  font-size: 2.2rem;
  font-weight: 700;
  margin-bottom: 8px;
}

header .subtitle {
  font-size: 1.05rem;
  opacity: 0.92;
}

/* Main layout */
.main-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 24px;
  padding: 24px;
  align-items: start;
}

.canvas-section {
  padding: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.canvas-container {
  background: #fff;
  border-radius: var(--radius);
  padding: 12px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  width: 100%;
  max-width: 680px;
}

#gridCanvas {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 4px;
  image-rendering: pixelated;
}

.canvas-legend {
  display: flex;
  gap: 18px;
  margin-top: 12px;
  flex-wrap: wrap;
  justify-content: center;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.legend-swatch {
  width: 16px;
  height: 16px;
  border-radius: 3px;
  border: 1px solid rgba(0, 0, 0, 0.12);
}

.legend-swatch.type-a {
  background: var(--type-a-color);
}
.legend-swatch.type-b {
  background: var(--type-b-color);
}
.legend-swatch.empty {
  background: var(--empty-color);
}
.legend-swatch.moved {
  background: #e040fb;
  box-shadow: 0 0 6px #e040fb;
}

/* Sidebar */
.sidebar {
  background: transparent;
  border-left: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
  overflow: visible;
  max-height: none;
  align-self: start;
  position: sticky;
  top: 24px;
}

.panel {
  background: #fff;
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.panel h2 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--primary-dark);
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--primary);
}

/* Controls */
.control-group {
  margin-bottom: 14px;
}

.control-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.slider-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.slider-row input[type="range"] {
  flex: 1;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--border);
  border-radius: 3px;
  outline: none;
}

.slider-row input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  transition: transform 0.15s;
}

.slider-row input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

.slider-value {
  min-width: 42px;
  text-align: right;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--primary-dark);
}

.button-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 16px;
}

.btn {
  padding: 10px 16px;
  border: none;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  text-align: center;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}

.btn-secondary {
  background: #fff;
  color: var(--primary);
  border: 2px solid var(--primary);
}
.btn-secondary:hover {
  background: var(--primary);
  color: #fff;
}

.btn-accent {
  background: var(--accent);
  color: #fff;
  grid-column: 1 / -1;
}
.btn-accent:hover {
  background: #e64a19;
  transform: translateY(-1px);
}

/* Stats */
.stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.stat-item {
  background: var(--bg-light);
  padding: 10px;
  border-radius: 8px;
  text-align: center;
}

.stat-item.full-width {
  grid-column: 1 / -1;
}

.stat-label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.3px;
  margin-bottom: 4px;
}

.stat-value {
  display: block;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
}

.stat-value.highlight {
  color: var(--primary-dark);
}

.stat-value.highlight-green {
  color: var(--success);
}

.stat-value.highlight-red {
  color: var(--danger);
}

/* Education section */
.education-section {
  padding: 30px;
  border-top: 1px solid var(--border);
}

.info-box {
  background: linear-gradient(135deg, #e8eaf6, #c5cae9);
  padding: 24px;
  border-radius: var(--radius);
  border-left: 4px solid var(--primary);
  margin-bottom: 24px;
}

.info-box h3 {
  color: var(--primary-dark);
  margin-bottom: 10px;
  font-size: 1.2rem;
}

.info-box p {
  color: var(--text-primary);
  line-height: 1.8;
}

.insight-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 18px;
}

.insight-card {
  background: #fff;
  padding: 20px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border-top: 3px solid var(--accent);
  transition: transform 0.2s ease;
}

.insight-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.insight-card h4 {
  color: var(--accent);
  margin-bottom: 10px;
  font-size: 1rem;
}

.insight-card p {
  color: var(--text-secondary);
  font-size: 0.92rem;
  line-height: 1.7;
}

/* Footer */
footer {
  background: var(--bg-light);
  padding: 18px 30px;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.88rem;
  border-top: 1px solid var(--border);
}

/* Responsive */
@media (max-width: 960px) {
  .main-layout {
    grid-template-columns: 1fr;
    gap: 0;
    padding: 0;
  }

  .sidebar {
    border-top: 1px solid var(--border);
    background: var(--bg-light);
    max-height: none;
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    padding: 20px;
  }

  .sidebar .panel {
    flex: 1;
    min-width: 280px;
  }
}

@media (max-width: 640px) {
  body {
    padding: 8px;
  }

  header {
    padding: 24px 16px;
  }

  header h1 {
    font-size: 1.6rem;
  }

  header .subtitle {
    font-size: 0.92rem;
  }

  .canvas-section {
    padding: 12px;
  }

  .sidebar {
    flex-direction: column;
    padding: 12px;
  }

  .sidebar .panel {
    min-width: auto;
  }

  .education-section {
    padding: 16px;
  }

  .stat-grid {
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }

  .button-row {
    grid-template-columns: 1fr 1fr;
  }

  .canvas-legend {
    gap: 10px;
  }
}