css if you select the first th_html/css_WEB-ITnose of the first row of

css If you select the first th of the first line of <table class="aaa">

Reply to discussion (solution)

.aaa th:first-child

.aaa table>th

CSS adjacent selector and first-child are not supported by many browsers

Setting class Then choose! Adjacent selector IE support is not good!

CSS adjacent selector and first-child are not supported by many browsers
Then change to jquery, percentage support.

$('.aaa th:first').css(...);

Or add css rules directly to the first th.
<th >