为什么react-bootstrap按钮的字体大小与香草引导程序不同?

I have started using react-bootstrap but noticed the font size on the buttons seems to be different to the non-react version. For example non-react bootstrap the button appears like so:

enter image description here

And for react-bootstrap:

enter image description here

为什么字体不同?有办法改变吗?我已经检查了CSS样式表,并且我在react和non-react版本中都使用了相同的样式表。