Answers for "how to style html audio tag"

css customize audio player

audio {
    filter: sepia(20%) saturate(70%) grayscale(1) contrast(99%) invert(12%);
    width: 200px;
    height: 25px;
}

/*or*/

audio::-webkit-media-controls-panel

audio::-webkit-media-controls-mute-button

audio::-webkit-media-controls-play-button

audio::-webkit-media-controls-timeline-container

audio::-webkit-media-controls-current-time-display

audio::-webkit-media-controls-time-remaining-display

audio::-webkit-media-controls-timeline

audio::-webkit-media-controls-volume-slider-container

audio::-webkit-media-controls-volume-slider

audio::-webkit-media-controls-seek-back-button

audio::-webkit-media-controls-seek-forward-button

audio::-webkit-media-controls-fullscreen-button

audio::-webkit-media-controls-rewind-button

audio::-webkit-media-controls-return-to-realtime-button

audio::-webkit-media-controls-toggle-closed-captions-button

audio html tag

MIME Types for Audio Formats
Format	MIME-type
MP3		audio/mpeg
OGG		audio/ogg
WAV		audio/wav

If simply audio '<audio>' tag is written then audio controls will not appear on the web page.
and for showing audio controller we need to write controls attribute in audion tag '<audio controls>'.

Example
<audio controls>
  <source src="horse.mp3" type="audio/mpeg">
</audio>