Modified - [repo-diff] [sticky-ui] [navbar] Prevented sticky diff headers from sliding under the persistent navigation bar.

- 1 - I updated `web_src/css/repo.css` so the sticky repository diff summary bar, the sticky second-row file headers, and the diff file scroll anchor margin now all include `--persistent-navbar-offset`, keeping them visible below the navbar when `Keep the navigation bar visible while scrolling` is enabled.
- 2 - I extended the same offset handling to `#diff-file-tree` so the sticky diff file tree no longer slides under the diff summary bar after the persistent-navbar preference shifts the sticky stack downward.

.codex-history.md

@@ -789,3 +789,7 @@ History search guidance:
 
 157 - [2026-05-17 15:35:49] - v1.26.0-by-petru - Type: Fixed - [scripts] [custom-release] [release-target] Stopped release-target sync from requiring the remote release branch when an explicit target tag/ref is configured.
 - 1 - I updated [`.maintain-custom-release.sh`](/config/workspace/gitea-dev/gitea/.maintain-custom-release.sh) so `Sync upstream release target commits` validates only the configured `UPSTREAM_RELEASE_TARGET_REF` when one is set, instead of still failing on a missing local `upstream/release/...` remote-tracking branch after successfully fetching a target tag such as `v1.26.1`.
+
+158 - [2026-05-18 23:03:13] - v1.27.0-dev-169-g69356f6de0 - Type: Modified - [repo-diff] [sticky-ui] [navbar] Prevented sticky diff headers from sliding under the persistent navigation bar.
+- 1 - I updated `web_src/css/repo.css` so the sticky repository diff summary bar, the sticky second-row file headers, and the diff file scroll anchor margin now all include `--persistent-navbar-offset`, keeping them visible below the navbar when `Keep the navigation bar visible while scrolling` is enabled.
+- 2 - I extended the same offset handling to `#diff-file-tree` so the sticky diff file tree no longer slides under the diff summary bar after the persistent-navbar preference shifts the sticky stack downward.

web_src/css/repo.css

@@ -836,7 +836,7 @@ td .commit-summary {
   justify-content: space-between;
   align-items: center;
   position: sticky;
-  top: 0;
+  top: var(--persistent-navbar-offset, 0px);
   z-index: 8;
   padding: 7px 5px;
   margin: 0 -5px; /* negative margin so it covers active file shadow */
@@ -999,7 +999,7 @@ td .commit-summary {
 .diff-file-box {
   border: 1px solid transparent;
   border-radius: var(--border-radius);
-  scroll-margin-top: 47px; /* match .repository .diff-detail-box */
+  scroll-margin-top: calc(47px + var(--persistent-navbar-offset, 0px)); /* match .repository .diff-detail-box */
 }
 
 .file.editor .diff-file-box {
@@ -1615,8 +1615,8 @@ tbody.commit-list {
   line-height: inherit;
   position: sticky;
   padding-top: 0;
-  top: 47px;
+  top: calc(47px + var(--persistent-navbar-offset, 0px));
-  max-height: calc(100vh - 47px);
+  max-height: calc(100vh - 47px - var(--persistent-navbar-offset, 0px));
   height: 100%;
   overflow-y: auto;
 }
@@ -1707,7 +1707,7 @@ tbody.commit-list {
 
 .ui.attached.header.diff-file-header.sticky-2nd-row {
   position: sticky;
-  top: 44px; /* match .repository .diff-detail-box */
+  top: calc(44px + var(--persistent-navbar-offset, 0px)); /* match .repository .diff-detail-box */
   z-index: 7;
 }