Ensure consistant spacing throughout entire site.css.scss file.
Delete trailing whitespaces after block openings; Make intended capitalizations consistant throughout file; Align comment positions; Remove extra semicolons after some statements; Turn JS comments into CSS comments; Replace shorthand color codes with full, explicit code, and lowercase capital letters; Wrap background url params with single quotes; Add space between commas inside rgba params; Remove sporadic double-spacing between shorthand margin values;
Wrap bg url params with single quotes; Add explicit color codes with lowercase letters; Delete extra semicolons; Space between commas inside rgba params.
Wrap bg url params with single quotes; Add explicit color codes with lowercase letters; Delete extra semicolons; Space between commas inside rgba params.
Add word 'of' to bullet 1, to make sentence read correctly.
Add comma to prevent run-on sentence.
Add double hyphen (--), (i.e., dash) to paragraph two of Core Concepts. Correct English grammar requires dash delineation between 'aside' fragments.
Add 'the following' before colon, because everything to the left of a colon must be a full clause. Stopping at 'can contain' leaves the sentence open, and is incorrect.