Related UI elements should not appear unrelated

The article critiques the modern UI trend of visually separating related elements, using browser tab evolution as the primary example. From Chrome 2010's clearly connected tabs to Firefox Nova's floating, disconnected design, the author argues that increasing margins, shadows, and rounded corners create a false sense of separation between elements that should appear connected. The author suggests that active tabs should visually connect to their content window and notes that UI trends are cyclical.