assistant: Black toenails usually signal either a toe box that's too tight (crowding the nail bed during impact) or a shoe that's too short — both fixable with the right fit. Since you have wide feet, we need to prioritize shoes with a genuinely roomy forefoot, not just "standard" width claims. Looking at your options, most of the retrieved shoes have **standard forefoot width**, which won't solve your problem. The exception is the **Saucony Ride v19** — EDDBUD specifically notes it has a "wider heel (~5mm)" and Kofuzi praises its "wider footprint," which translates to more room in the toe box overall. At 255g and 38/30mm stack, it's a solid, traditional daily trainer that won't feel cramped. The **Mizuno Neo Zen v2** is maximal-cushion and well-regarded, but it's explicitly **narrow in the forefoot** — that would likely worsen your toenail issue, so I'd skip it. The **New Balance 1080 v15** and **Rebel v5** both have standard forefoot width, so they're not ideal for wide feet either. Before I lock in a recommendation: **Do you typically wear a half-size up or a full size up from your normal street-shoe size to get toe-box room?** That'll help me gauge whether the Ride v19's "wider" geometry is enough, or whether you'd benefit from going up a size in whatever shoe you choose.