body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: #f5f7fa;
}

.container {
  max-width: 700px;
  margin: 40px auto;
  padding: 30px;
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 5px 20px rgba(0,0,0,0.05);
}

h1 {
  color: #0077cc;
  text-align: center;
}

.subtitle {
  text-align: center;
  color: #555;
  margin-bottom: 25px;
}

.form label {
  display: block;
  margin-top: 15px;
  color: #333;
}

.form input {
  width: 100%;
  padding: 10px;
  font-size: 1rem;
  margin-top: 5px;
  border: 1px solid #ccc;
  border-radius: 6px;
}

button {
  margin-top: 20px;
  width: 100%;
  padding: 12px;
  background: #0077cc;
  color: white;
  font-size: 1rem;
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

button:hover {
  background: #005fa6;
}

.result {
  display: none;
  margin-top: 30px;
  color: #333;
}

.result h2, .result h3 {
  text-align: center;
  color: #0077cc;
}

.result p {
  font-size: 1rem;
  margin: 8px 0;
}

.tip {
  margin-top: 12px;
  color: #d35400;
  font-weight: 600;
  text-align: center;
}

/* Responsive canvas */
canvas {
  max-width: 100%;
  height: auto !important;
}