Developing your own Style
Whether you start using a W3.css Template or a design adapted from another design it is still important to develop your own style.
For example, the design you are looking at now was based on the W3.css Portfolio Template. If you look at the original you should be able to see the similarity, however, I have added considerably to that original layout.
The W3.css Templates
This website uses the "Nature Portfolio" W3.css template as a starting place. It has been modified extensively from what you see on their example.