UI UX Design for ES6 Based Site

We are looking for a UI UX developer that can create re-usable styles and take charge with UX flow. The site is currently being build in Aurelia and relies heavily on REST based communication. Our expectations would be to have styles & markup arranged in a way that would ensure browser compatibility for IE 11 to Edge along with Chrome, Safari and Firefox. The styles would need to be created in a way that allows them to be shared going forward. The styles also will need to be mobile friendly and have appropriate media queries where necessary. The code would need to go through our GIT source control and go through pull requests. We are also on CICD so there are testing phases between releases. Please contact me for further information.