body{font-family:Segoe UI,sans-serif;background:#f1f2f6;display:flex;justify-content:center;align-items:center;height:100vh;margin:0}.container{background:#fff;padding:2rem;border-radius:12px;box-shadow:0 4px 14px #0000001a;text-align:center;width:100%;max-width:400px}input{width:100%;padding:.7rem;margin-bottom:1rem;border-radius:6px;border:1px solid #ccc;font-size:1rem}button{width:100%;padding:.7rem;background:#007bff;color:#fff;border:none;font-weight:700;border-radius:6px;cursor:pointer;font-size:1rem}button:disabled{background:#6c757d;cursor:not-allowed}.result{margin-top:1rem;font-weight:700}