edit a theme for ecommerce website using CSS html Java

Hi, I have a store from [login to view URL] which is similar to other ecommerce platforms like shopify etc. however it won’t accept Shopify templates or any other templates without manually going to the code and writing the needed code. I need a person knowledgeable in CSS & Java script write code to improve the simplistic design and install a slider on the landing page. I have already bought a html/CSS template (not platform specific I.e not Shopify or woocommerce template) which includes all html css JavaScript codes including sliders. I need someone to access my account directly to the css editor to change it to be similar to the template either by borrowing chunks of code from the template or any other way you deem easier and better for clean code. Also, u need to keep in mind the backend allows small adjustments in logo placements, pictures, small ads. You need to make sure ur new code doesn’t interfere with these backend tasks. Total number of pages is 5-6. Template includes more than one layout for each page to reduce ur time and cut my cost. Other than that only a slider which is also included in the template and a logo. Attached bellow r screenshots for the css editor in my platform. The only way to change the design. I’m trying to finish on budget and with the least amount of bugs possible. I will have the work checked by pro developer for final approval.