/* 2. */
#menu ul {
	margin: 0;
	padding: 0;
}
#menu li {
	display: inline-block;
	list-style-type: none;
	background-color: #111;
}
#menu a {
	display: inline-block;
	padding: 5px 20px;
	text-decoration: none;
	color: #fefefe;
}

/* 3. */
#menu-control {
	color: white;
	padding: 5px 20px;
	cursor: pointer;
	background-color: #111111;
	display: none;
}

#menu-control-input {
	display: none;
}

#menu-control-input:checked + #menu {
	display: block;
}


@media all and (max-width: 700px) {
	#menu-control {
		display: inline-block;
	}

	/* 4. */
	#menu li {
		display: block;
	}

	/* 5. */
	#menu {
		display: none;
		counter-reset: item;
	}

	#menu li a::before {
		counter-increment: item;
		content: counter(item) ") ";
		color: orange;
	}
}

/* 6. */
#menu a::after {
	content: " " attr(data-state);
	color: red;
}

/* 7. */
#menu li:nth-child(2n) {
	background-color: #666;
}

/* 8. */
#custom-checkbox-input {
	display: none;
}

#custom-checkbox {
	overflow: hidden;
	width: 60px;
	height: 30px;
	border-radius: 30px;
	background: lightblue;
	position: relative;
	display: block;
	cursor: pointer;
}

#custom-checkbox::before {
	position: absolute;
	content: "";
	display: block;
	width: 30px;
	height: 30px;
	border-radius: 50%;
	background: red;
	left: 0;
	transition: all 0.2s ease;
}

#custom-checkbox-input:checked + #custom-checkbox::before {
	left: 100%;
	transform: translateX(-100%);
	background: green;
}