Create a clean, flat design for a graphic design creation web app

PixelPlotter

I am building a graphic design website where users can create graphics (web banners, social media assets etc.) by modifying existing templates or from scratch using a simple drag-and-drop interface. The concept is somewhat similar to canva.com and spark.adobe.com however this service is aimed only at auto dealerships in the United States. I'm using graphics for a Nissan auto dealership for the purpose of these mockups.

Take a look at canva.com and spark.adobe.com to get an idea of the overall functionality however, I am looking for a very clean, minimal, flat design with bold typography and subtle background color scheme. Overall, an eye-catching design that wins the potential clients during a PowerPoint presentation. Design for the 1440 X 900 px screen size.

I've provided a zip file that contains the rough sketch of each page along with all necessary graphics.

Please design the following four pages:

(1) Sign Up
(2) My Designs (HOMEPAGE)
(3) Create Design
(4) Custom Services - Video

I'm under a tight deadline for this project. I'd appreciate your prompt work.