In Input init function self.button:set_style is called with argument self.button_style but self doesn't have such element. There is self.style.button_style, but including into account how set_style works, self.style should be passed. Furthermore, table that is passed to set_style should have elements with the same names, as components based on this, so every variable in default style and Input.on_style_change with the name button_style should be renamed into button.
Finally Input.on_style_change doesn't pass changes to the button component, something like self.button:set_style(self.style) at the end with relevant checks should fix this.
UPD: default input style already has correct field called button, but it doesn't work without fixing Input.on_style_change
In Input init function
self.button:set_styleis called with argumentself.button_stylebutselfdoesn't have such element. There is self.style.button_style, but including into account howset_styleworks,self.styleshould be passed. Furthermore, table that is passed toset_styleshould have elements with the same names, as components based on this, so every variable in default style andInput.on_style_changewith the namebutton_styleshould be renamed intobutton. FinallyInput.on_style_changedoesn't pass changes to the button component, something likeself.button:set_style(self.style)at the end with relevant checks should fix this.UPD: default input style already has correct field called
button, but it doesn't work without fixingInput.on_style_change