Build store credit system for website

1) Store credit added to customer account when customer is logged in, colour of wording and icon of store credit to be similar to other colours of words in customer account dashboard for consistency (colour code : #21cfcc) 2) I can control amount of store credit to be given from backend system, that is I decide how much store credit to give 3) Store credit can be applied at checkout, any balance not covered by store credit, to be paid by customer at checkout 4) Able to keep track store credit was given for which order number and applied to which order number from backend system 5) Store credit given and utilised is automatically updated in customer account from backend system.