feat: apply board color to TopBar border and column header accents

src/components/board/ColumnHeader.tsx

@@ -17,9 +17,10 @@ import type { Column, ColumnWidth } from "@/types/board";
 interface ColumnHeaderProps {
   column: Column;
   cardCount: number;
+  boardColor?: string;
 }
 
-export function ColumnHeader({ column, cardCount }: ColumnHeaderProps) {
+export function ColumnHeader({ column, cardCount, boardColor }: ColumnHeaderProps) {
   const [editing, setEditing] = useState(false);
   const [editValue, setEditValue] = useState(column.title);
   const inputRef = useRef<HTMLInputElement>(null);
@@ -59,7 +60,7 @@ export function ColumnHeader({ column, cardCount }: ColumnHeaderProps) {
   }
 
   return (
-    <div className="flex items-center justify-between border-b border-border px-3 pb-2 pt-3">
+    <div className="flex items-center justify-between border-b border-border px-3 pb-2 pt-3" style={{ borderTop: boardColor ? `3px solid ${boardColor}30` : undefined }}>
       <div className="flex items-center gap-2 overflow-hidden">
         {editing ? (
           <input

src/components/board/KanbanColumn.tsx

@@ -75,7 +75,7 @@ export function KanbanColumn({ column, onCardClick }: KanbanColumnProps) {
     >
       {/* The column header is the drag handle for column reordering */}
       <div {...listeners}>
-        <ColumnHeader column={column} cardCount={column.cardIds.length} />
+        <ColumnHeader column={column} cardCount={column.cardIds.length} boardColor={board?.color} />
       </div>
 
       {/* Card list - wrapped in SortableContext for within-column sorting */}