body { font-family: 'Inter', sans-serif; background: #f4f7f6; display: flex; justify-content: center; padding: 50px; }
.container { max-width: 500px; width: 100%; text-align: center; }
.calculator-card { background: white; padding: 30px; border-radius: 15px; box-shadow: 0 10px 25px rgba(0,0,0,0.1); }
input, select { width: 100%; padding: 12px; margin: 10px 0; border: 1px solid #ddd; border-radius: 8px; box-sizing: border-box; }
button { width: 100%; background: #007bff; color: white; padding: 15px; border: none; border-radius: 8px; cursor: pointer; font-weight: bold; }
button:hover { background: #0056b3; }
.result-area { margin-top: 20px; padding: 20px; background: #e9f5ff; border-radius: 8px; }
.buy-btn { display: inline-block; background: #28a745; color: white; padding: 10px 20px; text-decoration: none; border-radius: 5px; margin-top: 10px; }
.premium-text { font-size: 0.9em; color: #555; }