body {
  margin: 0;
  padding: 20px;
  font-family: 'Segoe UI', sans-serif;
  background: #1a1a1a;
  color: #fff;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
}

h1 {
  text-align: center;
  margin-bottom: 2rem;
  color: #4CAF50;
}

.controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

button {
  padding: 1rem;
  background: #4CAF50;
  border: none;
  border-radius: 4px;
  color: white;
  cursor: pointer;
  transition: transform 0.2s;
}

button:hover {
  transform: translateY(-2px);
}

.metrics {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-bottom: 2rem;
}

.metric {
  background: #2d2d2d;
  padding: 1.5rem;
  border-radius: 8px;
  text-align: center;
}

.label {
  display: block;
  font-size: 0.9rem;
  color: #888;
}

.value {
  font-size: 1.5rem;
  font-weight: bold;
}

#chart {
  background: #2d2d2d;
  border-radius: 8px;
  padding: 1rem;
}