Responsive single price grid component using HTML, CSS and Bootstrap4

Hi all,

I am very bad on CSS even if I keep trying it since long time now, I am very dependant on Bootstrap specially for grid design. I have to tell I code CSS by trying many different declarations until I get the result, I don't always know which declaration I should use, I think is one but then it's not... In short I really suck at CSS and design... I was able to accomplish this challenge but I think there is a lot which could be better, please your feedback is more than welcome I really need it...

Thanks in advance, Diogo