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>

frontend/src/editor/editor.css

@@ -37,11 +37,15 @@
      text used to run the full width of the pane, past 84, which is beyond the
      point where the eye reliably finds the start of the next line. Capped here
      rather than on the container so it holds on a page as well as off one. */
-  max-width: 527px;
-  /* Centred. Pinning the column to the left edge put every line in the same
-     place, but on a wide window it left the whole right half of the pane as one
-     dead block — which is worse to look at than a column that moves. Centred,
-     the same leftover space reads as two margins. */
+  /* Roughly 80 characters to the line, leaving about 8% of the sheet as margin
+     on either side — a document's margin, not a picture frame. It was 527px,
+     which left 117px of empty paper down each edge and made the writing look
+     lost on the page. Past about 84 characters the eye stops reliably finding
+     the start of the next line, so this is close to as wide as it should go. */
+  max-width: 640px;
+  /* Centred on the sheet. Pinning the column to the left edge put every line in
+     the same place, but on a wide window it left the whole right half of the
+     pane as one dead block. */
   margin-left: auto;
   margin-right: auto;
   outline: none;
@@ -69,6 +73,13 @@
   pointer-events: none;
   user-select: none;
 }
+/* The placeholder extension styles `[contenteditable]:empty::before`, and a
+   spacer is exactly that: empty, and not editable. So "Start writing..." was
+   printed at the foot of every page that had a break after it. */
+.note-editor .ProseMirror > .ne-page-spacer::before,
+.note-editor .ProseMirror > .ne-page-spacer::after {
+  content: none !important;
+}
 .note-editor .ProseMirror p {
   margin: 0;
 }