body {
  font-family: Arial, sans-serif;
  background: #0f172a;
  color: white;
  margin: 0;
}

.container {
  max-width: 800px;
  margin: auto;
  padding: 40px;
}

header {
  text-align: center;
  margin-bottom: 30px;
}

.invoice-form {
  background: #111827;
  padding: 20px;
  border-radius: 10px;
}

.row {
  display: flex;
  gap: 10px;
  margin-bottom: 10px;
}

input {
  flex: 1;
  padding: 10px;
  border-radius: 6px;
  border: none;
}

button {
  margin-top: 10px;
  padding: 10px 15px;
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

button.primary {
  background: #2563eb;
  color: white;
  width: 100%;
  margin-top: 20px;
}

.item {
  display: flex;
  gap: 10px;
  margin-bottom: 10px;
}

.item input {
  flex: 1;
}

.totals {
  margin-top: 15px;
  font-size: 18px;
}