css text ::selection with round corners

I saw this selection in VSCode and monaco-editor and it looks really good :

SO I tried to recreate this, here is my effort :

#ta{
  font-size : 18px;
}
#ta::selection{
  background : rgba(173, 216, 130, 0.9);
  border : 1px solid transparent;
  border-radius : 15px;
}

<textarea id="ta"></textarea>

But this doesn't get the round corners effect(I hope you get it) like the one shown in the picture.

Please help me out. Answers appreciated.