What I want to say here is like some kind of add-on on @Suciu Lucian's answer.
The weird situation I ran into is that when I apply the solution of @Suciu Lucian in my file, it works in Chrome but not in Safari (and did not try in Firefox). After I studied the guide of styling table border published by w3.org, I found something alternative:
table.myTable{
border-spacing: 0;
}
table.myTable td{
border-bottom:1px solid red;
}
Yes you have to style the td
instead of the tr
.