Mobile-Friendly Tumblr Theme

I need a fully custom Tumblr theme coded from scratch that puts clean, readable text at the center while still letting each post carry a few photos and decorative dividers. The aesthetic I’m after is modern, with a bright and vibrant palette that pops on both light and dark device settings. Everything has to scale perfectly on phones and tablets, so responsive HTML5, CSS3 Flexbox/Grid and a touch of JavaScript for any interactive bits are essential.

Navigation should live in a tidy side menu bar—slide-out or fixed is fine as long as it stays intuitive and doesn’t crowd the content. Within each text post I’d like easy-to-edit divider styles (think subtle lines, dots, or gradient blocks) that separate sections without overwhelming the eye. Image handling has to respect Tumblr’s native editor yet maintain consistent widths, lazy-load where possible, and keep captions lined up neatly.

Deliverables
• One install-ready .html theme file with embedded or linked style sheets and scripts
• Clear comments in the code so I can tweak colors and divider styles later
• A short setup guide covering upload, custom options, and how to add new dividers/photos in a post
• Cross-browser testing (latest Chrome, Firefox, Safari, Edge) plus Tumblr’s mobile app preview

If you’ve built responsive Tumblr themes before and can show a couple of live examples, that will help me move quickly to awarding the job.