<style>
div {
  border: solid 1px black;
  width: 200px;
  font-size: 20px;
  font-family: Monospace;
}
rt {
 font-size: 5px;
}
span {
    white-space: nowrap;
}
</style>
PASS if base does not wrap
<div>before ruby <ruby><span>b a s e</span><rt>annotation</rt></ruby> after ruby</div>
<div>before ruby <ruby>b a s e<rt>annotation</rt></ruby> after ruby</div>