<style>
div {
    position: relative;
    width: 50px;
    height: 50px;
    margin-bottom: 5px;
}
img {
    max-width: 100%;
    max-height: 100%;
}

#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;
    min-width: 30px;
    min-height: 30px;
}

#results {
    width: initial;
    height: initial;
    max-width: initial;
    max-height: initial;
}
</style>

<!-- auto sizing within constrained bounds -->
<div><img id="a" src="badchess-wide.png"></div>

<!-- auto sizing within constrained bounds and aspect ratio -->
<div><img id="b" src="badchess-wide.png"></div>

<!-- auto sizing within constrained bounds and aspect ratio -->
<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 min constraints -->
<div><img id="f" src="badchess-wide.png"></div>

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