body {
  font-family: "Poppins", sans-serif;
  background: #f7f9fc;
  color: #222;
  text-align: center;
  margin: 0;
  padding: 0;
}

header {
  background: linear-gradient(90deg, #0078d4, #00aaff);
  color: white;
  padding: 1.2rem 0;
  margin-bottom: 20px;
}

.controls {
  margin-bottom: 20px;
}

button {
  background-color: #0078d4;
  color: white;
  border: none;
  padding: 10px 16px;
  border-radius: 4px;
  cursor: pointer;
  margin-left: 10px;
}

button:hover {
  background-color: #005ea2;
}

.chart-section {
  width: 80%;
  margin: 0 auto;
  max-width: 700px;
}

#summary {
  margin-top: 30px;
  font-size: 1.1em;
  color: #333;
}