I have an existing site that looks great on a desktop monitor but breaks down as soon as the viewport shrinks. The task is to add or refine media queries so every page feels seamless on mobile phones, tablets and full-size desktops, using standard breakpoints you’re already comfortable with. The navigation bar must collapse cleanly and stay easy to tap, images and other media need to scale without distortion, and the overall text layout should re-flow so there is never a horizontal scroll bar. Flexbox or CSS Grid is fine if it helps, but keep the styling vanilla—no heavy frameworks unless you can justify the benefit. Deliverables • A revised CSS (or SCSS) file with well-commented media queries • Any minor HTML adjustments required for the new breakpoints • A concise change log summarising what was modified