Can I run CalcSteel on a mobile phone or tablet?

Yes. CalcSteel works in any modern browser including Safari on iOS, Chrome on Android, and mobile Firefox. The 3D editor uses WebGL and is touch-friendly for panning, rotating and zooming. On phones, the interface adapts to a compact layout: the sidebar collapses, the toolbar stays at the bottom, and the 3D canvas takes the full screen. That said, for serious modeling work we recommend a tablet (iPad, Android 10″+) or a laptop — the larger screen makes it much easier to select nodes, bars and work with panels. Complex projects with hundreds of bars are painful on a phone but still possible.