*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:#f8fafc;color:#1e293b;line-height:1.6}.container{min-height:100vh;display:flex;flex-direction:column;align-items:center;padding:2rem 1rem}.calculator{background:#fff;padding:2rem;border-radius:12px;box-shadow:0 4px 20px rgba(0,0,0,.1);width:100%;max-width:500px}.title{font-size:2rem;font-weight:700;text-align:center;color:#1e40af;margin-bottom:1.5rem}