【注释】标准图章，滑动浏览时，可能同时存在多个图章显示被选中的阴影的情况

PDF Office/PDF Master/Class/PDFWindowController/Side/RightSide/StampList/KMAnnotationStampViewController.swift

@@ -1236,6 +1236,7 @@ let KMPDFDynamicStampNeedAuthorKey1 = "km_pdfview_dynamic_stamp_need_author"
             }
 
             cellView.wantsLayer = true
+            cellView.layer?.backgroundColor = NSColor.clear.cgColor
             cellView.mouseMoveCallback = { [weak self] mouseEntered in
                 guard let self = self else { return }