What is a breakpoint in responsive web design?
The points at which a media query is introduced are known as breakpoints
What is the advantage of using a percentage (50%) width instead of a fixed (px) width for a “column” class in a responsive layout?
using relative units allows your content to maintain ratio. Allows the page to dynamically adapt as your screen size changes.
If you introduce CSS rules for a smaller min-width after the styles for a larger min-width in your style sheet, the CSS rules for the smaller min-width will “win.” Why is that?
Order matters, source order.