styles.css

body {
  font-family: Arial, sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  background-color: #f4f4f9;
}

.container {
  border: 2px solid #333;
  background-color: #ffffff;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
  text-align: center;
}

h1 {
  color: #333;
}

input,
select {
  margin: 10px 5px;
  padding: 10px;
  font-size: 16px;
  border-radius: 4px;
  border: 1px solid #ccc;
  background-color: #f9f9f9;
}

select {
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  background: url('data:image/svg+xml;utf8,<svg fill="%23333" height="24" viewBox="0 0 24 24" width="24" xmlns="http://www.w3.org/2000/svg"><path d="M7 10l5 5 5-5z"/></svg>')
    no-repeat right 3px center;
  padding-right: 30px;
}

button {
  margin: 20px 0;
  padding: 10px 20px;
  font-size: 16px;
  border-radius: 4px;
  border: none;
  background-color: #007bff;
  color: #fff;
  cursor: pointer;
}

button:hover {
  background-color: #0056b3;
}

#result {
  margin-top: 20px;
  font-size: 18px;
  font-weight: bold;
  color: #333;
  border: 1px solid #ccc;
  padding: 10px;
  border-radius: 4px;
  background-color: #aeffb2;
}