Restore form spacing and tone down more dark-theme accents

- Bootstrap 5 also removed `.form-group` (row bottom margin) and `.help-block`
  (muted helper text); both are used across the settings and query-log forms,
  so restore them. This recovers the vertical spacing that was missing between
  form rows throughout the interface.
- Dark theme: mute the active pagination link and the filled `.card-info` /
  `.card-primary` card headers (e.g. the query-log "Advanced filtering" box),
  which used Bootstrap's over-bright `#0d6efd`/`#0dcaf0` on the dark background.
  The headers are recoloured via AdminLTE 4's `--lte-card-variant-*` variables.
- Widen the reverse-DNS servers table's "Enabled" column so its header no
  longer overflows into the next column.

Signed-off-by: DL6ER <dl6er@dl6er.de>

Author: DL6ER

scripts/js/settings-dns.js

@@ -167,7 +167,7 @@ function createRevServerTable() {
     data: tableRows,
     autoWidth: false,
     columns: [
-      { data: "enabled", width: "54px", className: "revserver-chkbox text-center" },
+      { data: "enabled", width: "76px", className: "revserver-chkbox text-center" },
       { data: "network", className: "revserver-network" },
       { data: "ip", className: "revserver-ip" },
       { data: "domain", className: "revserver-domain" },

style/pi-hole.css

@@ -73,6 +73,19 @@
   gap: 0.5rem;
 }
 
+/* Bootstrap 5 removed `.form-group` (which carried the bottom margin between
+   form rows) and `.help-block` (muted helper text). The templates still use
+   both throughout, so restore their spacing/appearance rather than rewrite
+   every form to `.mb-3`/`.form-text`. */
+.form-group {
+  margin-bottom: 1rem;
+}
+.help-block {
+  display: block;
+  margin-top: 0.25rem;
+  color: var(--bs-secondary-color);
+}
+
 /* AdminLTE 4 no longer swaps the mini/full logo in the header when the sidebar
    is collapsed, so the full "Pi-hole" wordmark stays and wraps in the narrow
    header. Show the compact "Ph" mark while collapsed instead. */

style/themes/default-dark.css

@@ -35,6 +35,25 @@ body {
 h4 {
   color: #3c8dbc;
 }
+/* Tone down Bootstrap's bright accent fills, which are too saturated on the
+   dark background (the active page link and the filled coloured card headers
+   such as the query-log "Advanced filtering" box). */
+.page-item.active > .page-link {
+  background-color: #3c8dbc;
+  border-color: #3c8dbc;
+}
+.card-info {
+  --lte-card-variant-bg: #256170;
+  --lte-card-variant-bg-rgb: 37, 97, 112;
+  --lte-card-variant-color: #d6eef5;
+  --lte-card-variant-color-rgb: 214, 238, 245;
+}
+.card-primary {
+  --lte-card-variant-bg: #285a7a;
+  --lte-card-variant-bg-rgb: 40, 90, 122;
+  --lte-card-variant-color: #d6e5f2;
+  --lte-card-variant-color-rgb: 214, 229, 242;
+}
 .callout h4 {
   color: inherit;
 }