Bookmark Landing Page

Desktop design only. I have a few questions on how to fix some issues:

-How do I get the proper dimensions for the image sizes on the Features component? You can see that the different images that populate the left-hand side will cause the overall site layout height to change, and content will jump.

-How do I make the green ::before on the Features image & Header image stay fixed-in-lace relative to the accompanying image, when the viewport width is made more narrow? And how do I make the ::before's dimensions stay constant on scaling while using responsive units like percentage?

-How do I adjust color of the text but not the icon in the SVG logo in the footer, which needs white text instead of black?

Thank you! I greatly appreciate any help. :)