body {
  font-family: Arial, sans-serif;
  background: #f1f1f1;
  padding: 20px;
  color: #333;
}

.container {
  max-width: 800px;
  margin: auto;
  background: #fff;
  padding: 30px;
  border-radius: 10px;
  box-shadow: 0 0 15px rgba(0,0,0,0.1);
}

h1 {
  text-align: center;
  color: #0066cc;
}

.input-group, .output-group {
  display: flex;
  margin-bottom: 20px;
  justify-content: space-between;
  align-items: center;
}

label {
  flex: 1;
}

input, select {
  flex: 2;
  padding: 10px;
  font-size: 16px;
}

.result-box {
  background: #e8f4fc;
  padding: 15px;
  border-radius: 5px;
  font-size: 18px;
  margin-bottom: 10px;
}

.section {
  margin-top: 40px;
}

.note {
  font-size: 14px;
  color: #555;
  text-align: center;
}

.calc-button {
  display: block;
  width: 100%;
  background-color: #007acc;
  color: white;
  border: none;
  padding: 15px;
  font-size: 16px;
  cursor: pointer;
  border-radius: 5px;
  margin-bottom: 30px;
}

.calc-button:hover {
  background-color: #005f99;
}