Website update 510 -- 2

Hi guys, Please read the project description carefully to the end and if you think this job will take longer then an hour or two, then please do not bid because I will not accept your bid!! The site is [login to view URL] Our previous developer could not complete the project because as he said unfortunately he is not that good WP developer as he should be to complete it. Anyhow he did part of the task (the admin part) So the task is When the Checkout button on the cart page is clicked and there is only 1 product(admin decision how many) for checkout, then a popup will advertise X% discount (admin decision the size of the discount) if at least 1 more product is bought. The popup have 2 buttons: "No Thanks" and "Show me more Tours". Clicking the first button redirects the user to the checkout. Clicking the second button will redirect to the front page. If the customer decides to add an extra product and to get the discount, this advertised discount should be applied automatically to the extra added product and a text string on the cart and on the checkout should mention it. As I said the part of the task is already done. There is a place in the admin where all these 3 parameters(on how many products the discount will be activated, the size of the discount and the text of the popup text) are chosen by the admin and then saved to a db table. Currently the popup is reading these values from that table. The point is tha discount value to be applied to the last added product(if it is not discounted already from other place) after the button Show me more tours is clicked Your edits/adds should be well viewed on every device mobile/tablet/desktop We expect clean and commented code. If you need to add code to [login to view URL] or [login to view URL] , it must be at the bottom of the files and needs to be well commented. Adding css using !important is not acceptable! All changes should be only in the theme child directory If you understood the task well, please start your bid with "I can" Thank you