body {
  font-family: Arial, sans-serif;
  text-align: center;
  margin-top: 50px;
  background-color: #f7f7f7;
}
h1 {
  font-size: 2.2rem;
  margin-bottom: 30px;
}
canvas {
  margin: auto;
  display: block;
  max-width: 90%;
  height: 450px !important;
}
#gauge {
  max-width: 600px;
  margin: 0 auto;
}