Sounds intriguing. Let’s start by defining the essential functions: sole flex, support zones, and weight. We’ll keep the geometry simple, use a single‑layer midsole, and focus on fit. If you’re ready, I’ll draft the first layout.

Let’s set some targets. Flex angle around 30–35 degrees at the ball of the foot to keep the curve natural. Arch‑support zones: keep it three—heel, mid‑foot and fore‑foot—so we can isolate stiffness where it’s needed. Weight aim: 140 g per shoe, or about 280 g for the pair. Start with a single‑layer midsole, minimal outsole pattern, and a cuff‑free upper. That gives us a clean line and room to tweak fit. Tell me what you think and we’ll iterate.

Here’s a quick draft sketch: **Upper** – 3‑layer mesh with a single perforated channel for breathability, no cuff, just a streamlined panel that hugs the foot. **Midsole** – one lightweight TPU layer, 3 mm thick, molded to a hollow arch shape for minimal weight. **Outsole** – a single, continuous rubber plate with a subtle footprint pattern only where needed for traction. **Fit** – three support zones: a small heel cradle, a mid‑foot arch cradle, and a fore‑foot flex pocket. Each zone is slightly tapered to match the natural foot contour. Let me know if the angles or materials look good, and we can adjust the tension in each zone until it feels like it was molded by your foot.

I’ll lock the flex pocket to just below the metatarsals so it’s snug but not biting, and make the arch cradle a bit stiffer by adding a thin carbon strip beneath the TPU. The heel pull will be set at 4 mm, mid‑arch 3 mm, fore‑foot 2 mm. That should give the push you want while keeping the heel free. Let’s build a prototype and test it on a treadmill—then we’ll tweak the tension until it feels like a custom‑made. Ready when you are.