I forget that initial only works on chrome, but you get the idea right? You need to override the 100% max-width style that’s applying to the slider image, otherwise it will resize on mobile and that’s not what you want(?).
Not unless you want to compromise the content within it.
The caption will be at different heights depending on people’s font style settings in their browsers, therefore you can’t rely on reducing styles like padding. If you set a fixed height the caption area will not resize when text increases, meaning text will be cut off.
As the slider is fluid it never has an absolute height, so you’d never know what height to set the caption in CSS.