The captions button isn't modal, it doesn't indicate if captions are on or off.
Accessibility-wise this isn't very good. Heck, even from a usability standpoint: no tooltips if I don't understand a button? Why? Those circular arrows might mean repeat (do they?), but all I know is clicking them restarts the music. If I hover, I'm not told what it should be doing. There aren't even alt= attributes or titles somewhere for screen readers... except for a useless aria-label ("undefined, Video demo").
Accessibility-wise this isn't very good. Heck, even from a usability standpoint: no tooltips if I don't understand a button? Why? Those circular arrows might mean repeat (do they?), but all I know is clicking them restarts the music. If I hover, I'm not told what it should be doing. There aren't even alt= attributes or titles somewhere for screen readers... except for a useless aria-label ("undefined, Video demo").