* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: Arial, sans-serif;
  background-color: #f4f4f4;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 20px;
}

h1 {
  text-align: center;
  margin-bottom: 20px;
  color: #333;
}

body > * {
  max-width: 500px;
  width: 100%;
}

#change-due {
  background-color: #fff;
  padding: 15px;
  border-radius: 8px;
  margin-bottom: 15px;
  min-height: 50px;
  color: #2c3e50;
  font-weight: bold;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

#total {
  font-size: 1.5rem;
  font-weight: bold;
  margin-bottom: 15px;
  color: #e74c3c;
}

label {
  display: block;
  margin-bottom: 8px;
  font-weight: bold;
}

input {
  width: 100%;
  padding: 10px;
  border: 2px solid #ccc;
  border-radius: 5px;
  font-size: 1rem;
  margin-bottom: 10px;
}

input:focus {
  outline: none;
  border-color: #3498db;
}

button {
  width: 100%;
  padding: 12px;
  background-color: #3498db;
  color: white;
  border: none;
  border-radius: 5px;
  font-size: 1rem;
  font-weight: bold;
  cursor: pointer;
  margin-bottom: 20px;
}

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

#cash-drawer-display {
  background-color: #fff;
  padding: 15px;
  border-radius: 8px;
  white-space: pre-line;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  font-family: monospace;
}