* {
  box-sizing: border-box;
  font-family: Arial, sans-serif;
}

body {
  min-height: 100vh;
  background: #0f172a;
  color: #fff;
  text-align: center;
  padding-top: 80px;
}

h2 {
  margin-bottom: 20px;
}

input, select, button {
  width: 260px;
  padding: 10px;
  margin: 10px auto;
  display: block;
  border-radius: 6px;
  border: none;
}

button {
  background: #38bdf8;
  font-weight: bold;
  cursor: pointer;
}

button:hover {
  background: #0ea5e9;
}

#result {
  margin-top: 15px;
  font-size: 18px;
}