2 changed files with 19 additions and 15 deletions
@@ -270,6 +270,10 @@ body {
 .btn-icon.wrap-toggle[aria-pressed="true"] { background: var(--accent); color: var(--bg); border-color: var(--accent); }
 /* #152: wrap ON must break long unbroken tokens mid-word and allow no horizontal scrolling */
 html[data-wrap] .codebody { white-space: pre-wrap; overflow-wrap: anywhere; word-break: break-all; overflow-x: hidden; }
 /* #167: overflow:hidden zeroes the flex auto-minimum, so the codebody must
   be told to fill the space left of the gutter or it collapses and the
   gutter (flex-shrink:0) consumes the whole row */
 html[data-wrap] .code .codebody { flex: 1 1 auto; min-width: 0; }
 html[data-wrap] .editor { white-space: pre-wrap; overflow-wrap: anywhere; word-break: break-all; overflow-x: hidden; }
 /* #152: with wrap on nothing may scroll horizontally, including the code container and mobile floats */
 html[data-wrap] .code { overflow-x: hidden; }
@@ -284,6 +288,12 @@ html[data-wrap] .float { overflow-x: hidden; }
  font-family: var(--font-mono); font-size: var(--code-fs); line-height: var(--code-lh);
  padding: 14px 0; display: flex; overflow-x: auto;
 }
 /* #167: the gutter must not drive the flex layout — its content width
   (row count × number width) shrinks the code column, which re-wraps lines,
   which grows the gutter: a feedback loop. Pin the gutter with a fixed
   basis, take its width out of the negotiation, and let the codebody take
   the rest. */
 .code .gutter { flex: 0 0 auto; width: 3ch; min-width: 3ch; overflow: visible; }
 .code .gutter { flex-shrink: 0; }
 /* gutter/code share line metrics; the editor gutter keeps its own padding (#50) */
 .code .gutter { padding-top: 0; padding-bottom: 0; }
@@ -786,3 +796,5 @@ button[type="submit"]:focus-visible,
 .toggle-inline { display: inline-flex; }
 .wrap-normal { word-break: normal; overflow-wrap: break-word; }
 .created-banner { display: block; }
 /* #167: gutter rows for wrapped paste view — one row per visual code line */
 .gutline { display: block; }
@@ -1,7 +1,7 @@
 // #167: with line wrapping on, a logical line can occupy several visual
 // lines; the gutter must show one number per VISUAL line. Per-line spans
-// give each logical line its own box so offsetTop order stays correct even
+// give each logical line its own box so its height identifies the wrapped
-// when highlighting spans cross no line boundaries.
+// row count; blank gutter rows keep numbers aligned with line starts.
 (function () {
  var body = document.getElementById('codebody');
  var gutter = document.getElementById('gutter');
@@ -31,9 +31,9 @@
      // Each logical line block occupies rows = height / line-height when
      // wrapped; its number sits on the first row and the remaining rows get
      // blank gutter lines so numbers stay aligned with line starts.
-      // The code column width must not change while measuring (the gutter is
+      // The gutter has a fixed CSS width now (.code .gutter), so its row
-      // flex-shrink:0 so its own row count never affects it), and renumber
+      // count never changes the code column width: measurement is stable
-      // must be idempotent to avoid a ResizeObserver feedback loop.
+      // with no measurement/layout feedback.
      var lh = parseFloat(getComputedStyle(body).lineHeight) || 1;
      gutter.textContent = '';
      var frag = document.createDocumentFragment();
@@ -61,19 +61,11 @@
  renumber();
  // Re-renumber on toggle (theme.js toggles data-wrap on <html>) and on any
-  // size change (paste of lots of text, window resize, zoom). Only width
+  // size change (paste of lots of text, window resize, zoom).
  // changes of the code column affect wrapping, so observe width only —
  // height changes caused by our own renumbering must not re-trigger.
  var mo = new MutationObserver(renumber);
  mo.observe(document.documentElement, { attributes: true, attributeFilter: ['data-wrap'] });
  var lastW = body.getBoundingClientRect().width;
  if (window.ResizeObserver) {
-    var ro = new ResizeObserver(function () {
+    var ro = new ResizeObserver(function () { renumber(); });
      var w = body.getBoundingClientRect().width;
      if (Math.abs(w - lastW) < 0.5) return;
      lastW = w;
      renumber();
    });
    ro.observe(body);
  } else {
    window.addEventListener('resize', renumber);