body{font-family:'Segoe UI',Tahoma,Geneva,Verdana,sans-serif;background:#f8f9fa;color:#212529}footer,header{text-align:center;margin-bottom:20px}.calculator-box{background:#fff;border-radius:12px;box-shadow:0 4px 12px rgba(0,0,0,.1);padding:20px}.result-box{font-size:1.5rem;font-weight:700;color:#0d6efd}.ad-box{background:#e9ecef;border:1px dashed #6c757d;text-align:center;margin:10px 0;padding:10px}.social-buttons button{margin:5px}