thunderbird css设置邮件标题行高及字体失效

thunderbird css设置邮件标题行高及字体失效
请问如何设置，要把chrome.css文件要放在哪个位置
另外css文件编码如下，是否可以？
/* 全域参数 */
* {font-family:Microsoft YaHei  !important}
font-weight: bolder !important;
* {font-size: 12px !important}

/* 信件列表 */
treechildren:-moz-tree-cell-text(unread) {
font-weight: bolder !important;
color: rgb(255,0,0) !important;
font-size: 16px !important;
font-family: Microsoft YaHei
http://soft.chinabyte.com/os/152/12309652.shtml !important;
}

treechildren:-moz-tree-cell-text(read){
color: rgb(17,46,60) !important;
font-size: 14px !important;
font-weight: bold !important;
font-family: Microsoft YaHei  !important;
}

/*邮件标题列表(选中状态)*/
#threadTree treechildren::-moz-tree-row(selected) {
background-color: #DADC9B !important;
color: rgb(218,220,155) !important;
}

treechildren:-moz-tree-row {
height: 24px !important;
}