body {
  font-family: Arial, sans-serif;
  max-width: 600px;
  margin: 0 auto;
  padding: 20px;
  line-height: 1.6;
}

h1 {
  color: #2c3e50;
  text-align: center;
}

.calculator {
  background-color: #f9f9f9;
  border-radius: 8px;
  padding: 20px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.input-group {
  margin-bottom: 15px;
}

label {
  display: block;
  margin-bottom: 5px;
  font-weight: bold;
}

input,
select {
  width: 100%;
  padding: 8px;
  border: 1px solid #ddd;
  border-radius: 4px;
  box-sizing: border-box;
}

button {
  background-color: #3498db;
  color: white;
  border: none;
  padding: 10px 15px;
  border-radius: 4px;
  cursor: pointer;
  width: 100%;
  font-size: 16px;
}

button:hover {
  background-color: #2980b9;
}

.result {
  margin-top: 20px;
  padding: 15px;
  background-color: #e8f4f8;
  border-radius: 4px;
  display: none;
}

.tab {
  overflow: hidden;
  border: 1px solid #ccc;
  background-color: #f1f1f1;
  border-radius: 4px 4px 0 0;
}

.tab button {
  background-color: inherit;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 10px 16px;
  transition: 0.3s;
  width: 50%;
  color: #333;
}

.tab button:hover {
  background-color: #ddd;
}

.tab button.active {
  background-color: #3498db;
  color: white;
}

.tabcontent {
  display: none;
  padding: 20px;
  border: 1px solid #ccc;
  border-top: none;
  border-radius: 0 0 4px 4px;
}

.unit-group {
  margin-top: 15px;
}

.unit-title {
  font-weight: bold;
  margin-bottom: 5px;
}