src/librustdoc/html/static/css/settings.css

.setting-line {
	margin: 1.2em 0.6em;
	position: relative;
}

.setting-radio input, .setting-check input {
	margin-right: 0.3em;
	height: 1.2rem;
	width: 1.2rem;
	color: inherit;
	border: 1px solid currentColor;
	outline: none;
	-webkit-appearance: none;
	cursor: pointer;
}
.setting-radio input {
	border-radius: 50%;
}
.setting-check input:checked {
	content: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 40 40">\
		<path d="M7,25L17,32L33,12" fill="none" stroke="black" stroke-width="5"/>\
		<path d="M7,23L17,30L33,10" fill="none" stroke="white" stroke-width="5"/></svg>');
}

.setting-radio span, .setting-check span {
	padding-bottom: 1px;
}

.setting-radio {
	margin-top: 0.1em;
	margin-bottom: 0.1em;
	min-width: 3.8em;
	padding: 0.3em;
	display: inline-flex;
	align-items: center;
	cursor: pointer;
}
.setting-radio + .setting-radio {
	margin-left: 0.5em;
}

.setting-check {
	margin-right: 20px;
	display: flex;
	align-items: center;
	cursor: pointer;
}

.setting-radio input:checked {
	box-shadow: inset 0 0 0 3px var(--main-background-color);
	background-color: var(--settings-input-color);
}
.setting-check input:checked {
	background-color: var(--settings-input-color);
}
.setting-radio input:focus, .setting-check input:focus {
	box-shadow: 0 0 1px 1px var(--settings-input-color);
}
/* In here we combine both `:focus` and `:checked` properties. */
.setting-radio input:checked:focus {
	box-shadow: inset 0 0 0 3px var(--main-background-color),
		0 0 2px 2px var(--settings-input-color);
}
.setting-radio input:hover, .setting-check input:hover {
	border-color: var(--settings-input-color) !important;
}