The project has one basis: 엑셀 z (default) or 도면 EL.X. On ②, the bearing card lists EL.X, h1 and h2 for each bearing (per pier), with a button to fill the reference values. With the drawing basis the model takes the drawing EL.X as the bearing height; the coping tops stay within the 5 mm tolerance, the front block is 164 mm and the back 139 mm (excluding the pad). The check compares EL.X − h1 − h2 with the Excel-basis coping top. The basis and the drawing values are saved in the project file (optional fields). Changes regenerate every pier at once. Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>