You can apply more advanced styling to the HTML5 PRO player using Cascading Stylesheet (CSS). Know more about CSS here
Few examples can be utilized below:
To make the player background transparent:
.playerYess .metadata, .playerYess .volume-wpr {
background-color: transparent !important;
}
To hide Like Button:
#icon-like { display: none !important; }
To hide Download Button:
#icon-download { display: none !important; }
To hide close button:
#icon-close { display: none !important; }
To hide all icons at once:
.playerYess .icons