body {
  font-family: Arial, Helvetica, sans-serif;
  background: linear-gradient(135deg, #eef2f7, #e3e9f3);
  margin: 0;
  padding: 0;
}

.container {
  max-width: 750px;
  margin: 40px auto;
  background: #ffffff;
  padding: 30px;
  border-radius: 12px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
  text-align: center;
}

h1 {
  margin-bottom: 10px;
}

p {
  color: #555;
}

button {
  background: #2b3a67;
  color: #fff;
  border: none;
  padding: 12px 20px;
  margin: 8px;
  border-radius: 8px;
  font-size: 16px;
  cursor: pointer;
  transition: 0.3s;
}

button:hover {
  background: #1d2748;
}

.result {
  margin-top: 25px;
  font-size: 24px;
  font-weight: bold;
  color: #111;
  background: #f4f6fb;
  padding: 20px;
  border-radius: 10px;
}

.copy {
  margin-top: 15px;
  background: #4caf50;
}

.copy:hover {
  background: #3e8e41;
}