Can a website or web-app can be developed using material design(flat) for a mobile browsers ?? Example:chrome,Firefox etc.
Material design is a guideline that is meant to be used for any device. Although it has practices and recommendations for Mobiles it usually gives tips for desktops too, so it is independent of being for an app a web on desktop or mobile.
Develop a single underlying system that allows for a unified experience across platforms and device sizes. Mobile precepts are fundamental, but touch, voice, mouse, and keyboard are all ﬁrst-class input methods.
You can check design awards they give every year, where there are different ways of implementing Material design.