body {
  font-family: 'Segoe UI', sans-serif;
  background: #f0f4f8;
  margin: 0;
  padding: 0;
  text-align: center;
}
header {
  background: #004080;
  color: white;
  padding: 20px 10px;
}
h1 {
  margin: 0;
  font-size: 2em;
}
.container {
  display: flex;
  flex-direction: column;
  gap: 20px;
  max-width: 600px;
  margin: auto;
  padding: 20px;
}
.card {
  background: white;
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
.value {
  font-size: 2.5em;
  margin-top: 10px;
  color: blue;
}
canvas {
  width: 100%;
  height: 150px;
  border: 1px solid #ccc;
  background: #fff;
}
footer {
  margin-top: 30px;
  font-size: 0.9em;
  color: #333;
}