[mau]

A framework is not only a good way to start. It's also a good way to uniform code, make things easier for new comers (larger projects usually have lots of new people that eventually write code), solve multiple common issues you'd fight by your own (e.g. browsers compatibility), community support and documentation. If you write your own you need to document well all things and things very careful how to arrange css classes to make code reusable and flexible.