Replace wordpress with custom html & css using bootstrap on existing website

Our current website https://www.massageyoursenses.gr/ has been designed using wordpress. We would like to get rid of wordpress and re-write it from scratch using the latest bootstrap library. The design should be responsive, and the content should not change, just the underlying html & css code (i.e. the end user should not notice any change). The final html & css should be minimal (i.e. smaller files are better).