JSFiddle - React, Tailwind, and code Playground

HTML

<h1>How to style the little circle?</h1>
<video controls src="https://a.desu.sh/zflbzy.webm"><</video>

CSS

video::-webkit-media-controls-panel {
    background-color: #161618;
}

video::-webkit-media-controls-volume-slider-container {
	background-color: cyan;
}

video::-webkit-media-controls-volume-slider {
	background-color: #1FB2B0;
}

video::-webkit-media-controls-timeline {
	background-color: #1FB2B0;
}