<style>
div {
    margin-bottom: 5px;
}
img {
    width: 300px;
    height: 10px;
}

#b, #c, #e, #g {
    -webkit-aspect-ratio: from-intrinsic;
}

#d, #e {
    min-width: 20px;
    max-width: 20px;
    min-height: 20px;
    max-height: 20px;
}

#f, #g {
    width: auto;
    height: auto;
    max-width: 30px;
    max-height: 30px;
}

</style>

<!-- specified sizing -->
<div><img id="a" src="badchess-wide.png"></div>

<!-- intrinsic aspect ratio wide -->
<div><img id="b" src="badchess-wide.png"></div>

<!-- intrinsic aspect ratio tall -->
<div><img id="c" src="badchess-tall.png"></div>

<!-- specified sizing with min/max constraints -->
<div><img id="d" src="badchess-wide.png"></div>

<!-- specified sizing with min/max constraints and aspect ratio -->
<div><img id="e" src="badchess-wide.png"></div>

<!-- auto sizing with max constraints -->
<div><img id="f" src="badchess-wide.png"></div>

<!-- auto sizing with max constraints and aspect ratio -->
<div><img id="g" src="badchess-wide.png"></div>