* {
  box-sizing: border-box;
  font-family: 'Segoe UI', sans-serif;
  margin: 0;
  padding: 0;
}

body {
  background: #f2f4f8;
  padding: 20px;
}

.container {
  max-width: 640px;
  margin: 0 auto;
  background: white;
  padding: 24px;
  border-radius: 12px;
  box-shadow: 0 6px 20px rgba(0,0,0,0.08);
}

h2 {
  text-align: center;
  color: #333;
  margin-bottom: 20px;
}

form {
  margin-top: 15px;
}

form input[type="number"] {
  width: 100%;
  padding: 10px;
  margin: 8px 0 16px;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 1rem;
}

form input[type="submit"] {
  background-color: #0077cc;
  color: white;
  padding: 12px 16px;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.3s;
}

form input[type="submit"]:hover {
  background-color: #005fa3;
}

ul {
  padding-left: 20px;
  margin-top: 12px;
}

li {
  margin-bottom: 6px;
  line-height: 1.4;
}

p {
  font-size: 1rem;
  margin-top: 12px;
}

@media (max-width: 480px) {
  .container {
    padding: 16px;
  }

  h2 {
    font-size: 1.3rem;
  }

  form input[type="number"],
  form input[type="submit"] {
    font-size: 0.95rem;
  }

  p {
    font-size: 0.95rem;
  }
}