slide resizes font doesn't

i ahvea slideshow with text slides in the settings i have Proportional relationship between slideshow’s width and height (width:height) set as 4:1,

now when i resize the page the slide resizes but the font size doesn’t change at all which makes half the text disappear…how do i get the text to resize too with the width

https://ww.wp.xz.cn/plugins/slideshow-jquery-image-gallery/