body {
  font-family: Arial, sans-serif;
  padding: 2rem;
  background: #f1f5f9;
}
.container {
  max-width: 800px;
  margin: auto;
  background: #fff;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
input[type="number"] {
  width: 100%;
  padding: 0.5rem;
  margin: 0.5rem 0;
  border-radius: 5px;
  border: 1px solid #ccc;
}
label {
  font-weight: bold;
}
canvas {
  margin-top: 2rem;
}
a {
  font-size: 1.2rem;
  display: block;
  margin: 1rem 0;
}