feat: make checkbox column in member view sticky

assets/css/app.css

@@ -708,3 +708,68 @@
   background-color: transparent !important;
   color: inherit;
 }
+
+/*
+ * Default interactive table rows: neutral hover/focus-visible fill for clickable rows.
+ * Uses :has(:focus-visible) so keyboard navigation highlights the row without sticky mouse-focus artifacts.
+ */
+.table.table-zebra tbody tr[data-row-interactive="true"]:is(:hover, :has(:focus-visible)) > td {
+  background-color: var(--color-base-300);
+}
+
+/*
+ * Sticky first column in zebra tables: opaque backgrounds per row.
+ * Use nth-child (not HEEx row index) so LiveStream rows stay iterable only via :for (Phoenix LV requirement).
+ */
+[data-sticky-first-col-rows="true"] .table.table-zebra tbody tr:nth-child(odd) > td.sticky-first-col-cell {
+  background-color: var(--color-base-100);
+}
+
+[data-sticky-first-col-rows="true"] .table.table-zebra tbody tr:nth-child(even) > td.sticky-first-col-cell {
+  background-color: var(--color-base-200);
+}
+
+/*
+ * Checkbox-selected rows: keep zebra backgrounds; only accent the sticky checkbox column.
+ */
+[data-sticky-first-col-rows="true"]
+  .table.table-zebra
+  tbody
+  tr[data-selected="true"]
+  > td.sticky-first-col-cell {
+  box-shadow: inset 2px 0 0 var(--color-primary);
+}
+
+[data-sticky-first-col-rows="true"]
+  .table.table-zebra
+  tbody
+  tr[data-row-interactive="true"]:is(:hover, :has(:focus-visible))
+  > td.sticky-first-col-cell {
+  background-color: var(--color-base-300);
+  /* Left accent only; keep the familiar orange primary accent. */
+  box-shadow: inset 2px 0 0 var(--color-primary);
+}
+
+/*
+ * Sticky member selection table: drop mouse-only focus outlines that read like a thin frame around the row;
+ * keyboard :focus-visible keeps DaisyUI control outlines (checkbox / tabindex cell).
+ */
+[data-sticky-first-col-rows="true"] .table.table-zebra tbody tr {
+  outline: none;
+}
+
+[data-sticky-first-col-rows="true"]
+  .table.table-zebra
+  tbody
+  tr[data-row-interactive="true"]:is(:hover, :has(:focus-visible)):not(:last-child) {
+  /* DaisyUI draws a bottom border on each row; hiding it while highlighted avoids a boxy “frame”. */
+  border-bottom-color: transparent;
+}
+
+[data-sticky-first-col-rows="true"] .table.table-zebra tbody tr td:focus:not(:focus-visible) {
+  outline: none;
+}
+
+[data-sticky-first-col-rows="true"] .table.table-zebra tbody tr input.checkbox:focus:not(:focus-visible) {
+  outline: none;
+}