My desktop-only site is built with plain HTML and CSS across three pages—Index, Login, and Forgot Password. I now need it to behave flawlessly on mobiles and tablets while leaving the current desktop layout untouched. I will hand over: • The existing codebase (no framework involved). • JPEG/PNG mock-ups that show exactly how each page should appear on phone and tablet Your task is to introduce the necessary breakpoints and media queries, keep structural changes to a minimum, and mirror the supplied visuals pixel-for-pixel. No extra libraries or rewrites—just clean, well-commented CSS tweaks (or light HTML adjustments if absolutely required). The updated design should remain working on desktop-view and should also work on mobile and tablet (both portrait and landscape orientations) Deliverables at hand-off: • Updated HTML/CSS files ready to drop in. • A short change log summarizing what was modified. If this first batch goes smoothly, I plan to extend the same approach to the remaining pages in a follow-up project.