.gst-calculator {
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
  background: #f0fbf1;
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.calculator-inputs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 40px;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.input-group label {
  font-weight: 500;
  color: #333;
  font-size: 16px;
}

.input-group input,
.input-group select {
  padding: 12px;
  border: 1px solid #ddd;
  border-radius: 8px;
  font-size: 16px;
  width: 100%;
  background: #fff;
  appearance: none;
}

.input-group select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%23666' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 16px;
  padding-right: 40px;
}

.calculation-display {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  padding: 20px;
}

.amount-group {
  text-align: center;
}

.amount {
  font-size: 32px;
  font-weight: bold;
  margin-bottom: 8px;
}

.operator {
  font-size: 32px;
  font-weight: bold;
  color: #666;
}

.label {
  font-size: 14px;
}

.label.actual {
  color: #0066ff;
}

.label.gst {
  color: #00a651;
}

.label.total {
  color: #0066ff;
}

@media screen and (max-width: 768px) {
  .calculator-inputs {
    grid-template-columns: 1fr;
    gap: 15px;
  }

  .calculation-display {
    flex-direction: column;
    gap: 10px;
  }

  .operator {
    font-size: 24px;
  }

  .amount {
    font-size: 28px;
  }
}