Responsive CSS Media Queries Fix

I have an existing HTML/CSS layout that looks fine on desktop but falls apart on smaller view-ports. I only need targeted screen-size adjustments, focusing on mobile phones and tablets. The goal is a clean,... (Budget: ₹600 - ₹1500 INR, Jobs: CSS, CSS3, Frontend Development, HTML, HTML5, JavaScript, UI / User Interface, Web Design, Web Development, Web Testing)