body {
  font-family: Arial, sans-serif;
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
}

h1 {
  text-align: center;
}

#calculator {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 20px;
}

input, select, button {
  padding: 5px;
  font-size: 16px;
}

#result {
  font-weight: bold;
  margin-top: 10px;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  border: 1px solid #ddd;
  padding: 8px;
  text-align: left;
}

th {
  background-color: #f2f2f2;
}
