client/css/checkbox.css

.checkbox input {
	height: 0;
	width: 0;
	display: none;
}

.checkbox span {
	font-size: 0.875rem;
	color: var(--colour-2);
	margin-left: 4px;
}

.checkbox label:after {
	content: "";
	position: absolute;
	top: 50%;
	transform: translateY(-50%);
	left: 5px;
	width: 20px;
	height: 20px;
	background: var(--blur-border);
	border-radius: 90px;
	transition: 0.33s;
}

.checkbox input + label:after,
.checkbox input:checked + label {
	background: var(--colour-3);
}

.checkbox input + label,
.checkbox input:checked + label:after {
	background: var(--blur-border);
}

.checkbox input:checked + label:after {
	left: calc(100% - 5px - 20px);
}

@media screen and (max-width: 990px) {
	.checkbox label {
		width: 25px;
		height: 15px;
	}

	.checkbox label:after {
		left: 2px;
		width: 10px;
		height: 10px;
	}

	.checkbox input:checked + label:after {
		left: calc(100% - 2px - 10px);
	}
}