Flow state requires complete absorption with no competing stimuli. One paragraph at full opacity, everything else at 25% — the environment does the discipline for you.
The Flow Research
Mihaly Csikszentmihalyi spent 30 years studying optimal experience. His central finding: flow state requires complete absorption in the task with no competing stimuli.
The conditions are specific: clear goals, immediate feedback, and a balance between challenge and skill. But the prerequisite — the thing that must exist before any of those matter — is the absence of distraction.
A writing app that shows you a toolbar, a sidebar, a notification badge, and three open panels is an app that makes flow impossible by design.
Paragraph-Level Dimming
Focus Mode dims every paragraph except the one you are writing to a quarter of its normal contrast. The transition is 100ms — fast enough to feel instant, slow enough to feel gentle.
This is not aesthetic minimalism. This is environmental design based on the attention research: your visual field contains only one paragraph at full contrast. Everything else recedes.
The mechanism uses ProseMirror decorations — the same render cycle as the editor itself. No external JavaScript, no inline styles that break on re-render. Correct by construction.
Typewriter Scrolling
Typewriter scrolling runs at all times, in both modes: the line you are on is kept clear of the edges of the screen (a 100px band top and bottom). You never write at the bottom of the viewport.
This removes the micro-distraction of watching text push downward as you type. The cursor stays still. The page moves around it.
iA Writer, Ulysses, and Typora all implement this. The research is clear: a stable writing position reduces eye movement and maintains the sense of "writing in place" that flow requires.