Misaligned slotDuration lines in Safari when browser zoom is not 100%

<img width="325" height="529" alt="Image" src="https://github.com/user-attachments/assets/8938fbdc-1633-410b-a01d-d056c341b734" /> Chrome 90%

<img width="411" height="661" alt="Image" src="https://github.com/user-attachments/assets/00b3a46b-c210-43f2-b3bd-0675e2d3a973" />
Safari 80%

[CodePen](https://codepen.io/editor/aloysiu5/pen/019d6e2f-2d8c-7cd2-80d3-1ee0d0c6d887)