What is the toughest part about Design Web Application ?

How to find creative idea...

Security and user experience

Salam When it comes to web app development, i think the toughest part is security, as we all know web contents are always exposed

Karim said right toughest part is security an also write a CSS for different browsers.

well, to design a web application the toughest part is always defining User Experience and User Interface by the end of it, so a clean, to the point plan has to be laid out on paper beforehand and should be discussed in and out...it defines the goals clearly and then you can discuss the best approach to secure and program it.