When the logs for a step in a stage are very long, it becomes difficult to re-collapse that step to look at another or get back to the top of the pipeline to select another stage/ parallel branch etc. Instead of expanding the whole page, I think it would be better to have the log be inside a scrollable window with a max height of the window height minus some border for example (perhaps with a corner to drag down like multi-line text boxes. This would make the whole page length only the length of the graph, plus steps, plus the one expanded step with a log window of say 40 lines instead of potentially thousands of lines long.

This would help with the issue outlined in JENKINS-41885 when trying to monitor the logs of a running pipeline.