need java script expert ,, with html5 experience

Develop a dynamic background for my homepage and other website pages, that can be easily installed into the existing code I'm using. The background will be a partial spherical gradient surface in two colors, changing regularly in color and position. The appearance to the viewer is that my web page banner objects are floating inside a sphere looking out (so concave effect). You must have your own server for development of code, that you will submit to me for installation and testing on my website, to validate functional and appearance correctness. Project skills and resources required: - how to code html/css for a dynamic (in motion) spherical concave gradient two-color background; - how to vary the gradient colors and the gradient spatial position over time dynamically, so it’s a moving background (in motion); - how to apply the dynamic concave spherical two-color gradient to the background of my existing website homepage, such that existing banners are (floating) suspended in front of the moving background (or a video container); - necessary code structure so that page loading and page response times are acceptably short;