Keep the gap blank, and give the writing more of the page

Two things wrong with the paper.

"Start writing..." was printed at the foot of every page that had a break
after it. The placeholder extension styles `[contenteditable]:empty::before`,
and the spacer holding a gap open is exactly that: empty, and not
editable. It inherited a placeholder meant for an empty note.

And the column was too narrow for the sheet it now sits on — about 73
characters, which left 117px of blank paper down each edge and made the
writing look lost. Widened to about 80, a little short of where the eye
stops reliably finding the start of the next line, which leaves roughly
8% of the sheet as margin: a document's margin rather than a picture
frame.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -8,6 +8,20 @@ not from the output of `docker push`.
 
 ---
 
+## Unreleased
+
+**Changed**
+- **Narrower margins on the sheet** — the column went from about 73 characters
+  to about 80, leaving roughly 8% of the paper as margin either side instead of
+  117px of empty page down each edge.
+
+**Fixed**
+- **"Start writing..." was printed at the foot of every page with a break after
+  it.** The placeholder extension styles `[contenteditable]:empty::before`, and
+  the spacer holding a gap open is exactly that — empty, and not editable.
+
+---
+
 ## 2026-08-11 — Writing on paper
 
 **Images** — web `sha256:b764a9d8…`, server unchanged at `sha256:0832ee2b…`