为什么 treechildren selected 没有效果????userChrome.css

treechildren::-moz-tree-row(selected) { background-color: #FFFFAA; }
treechildren::-moz-tree-row(odd) { background-color: #EEEEEE; }
treechildren::-moz-tree-row(odd, selected) { background-color: #FFFFAA; }
treechildren::-moz-tree-cell-text(selected) { color: #000000; }
treechildren::-moz-tree-cell-text(odd, selected) { color: #000000; }