Custom landing page with CSS background animation on whole page

General information for the website: Landing page for new subscription product website
Kind of development: New website from scratch
Num. of web pages/modules: 1
Description of every page/module: Homepage will have repeating background motion-graphic/animation. Superimposed Call-To-Action button for email address/name capture and small area for copy describing business.

Single landing page required
Description of requirements/features: GIF or rolling animation in background, likely scripted into CSS3. Image concepts have been sketched but interested for creative input.

Limited budget for hosting so options open. Will be running email capture campaign for two months before full custom website finished and business start. Integration of call to action to mailchimp prefered

Can provide sketches of background image proposal if needed
Extra notes: Similar to:

http://states.design/

Background of this site https://eligo-bioscience.com/