Change Dom of Gmail using content script

Hello my dear friend! I can help with your project. I am experienced (4 years) developer with such stack of technologies: System administration: Linux, Apache, Nginx. Frontend: HTML, CSS, Bootstrap, JS (JQuery, svg, 3d, etc.). Backend: PHP, Wordpress, Codeigniter, Ruby on Rails. Databases: SQL and NoSQL databases. and little bit of Erlang, Python, Java, C++ and C#. I would be grateful to work with you! Please contact me as soon as you can. Skype - warriorswithin. Thanks! Best wishes, Vladimir.