app.css

.todoapp input[name="completedCount"][value="0"] ~ * input[name="clearCompleted"] {
    visibility: hidden;
}

.todoapp input[name="totalCount"][value="0"] ~ * {
	display: none;
}

.todoapp input[name="filter"][value="active"] ~ * .task :is(input[name="completed"]:checked, input[name="completed"]:checked ~ *),
.todoapp input[name="filter"][value="completed"] ~ * .task :is(input[name="completed"]:not(:checked), input[name="completed"]:not(:checked) ~ *) {
    display: none;
}

.todoapp input[name="filter"][value=""] ~ footer a[href$="#/"],
nav a:target {
    border-color: #CE4646;
}

input[type="submit"], input[type="button"] {
	margin: 0;
	padding: 0;
	border: 0;
	background: none;
	font-size: 100%;
	vertical-align: baseline;
	font-family: inherit;
	font-weight: inherit;
	color: inherit;
	-webkit-appearance: none;
	appearance: none;
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
}

.todo-list li input[name="title"] {
	word-break: break-all;
	padding: 15px;
	display: block;
	line-height: 1.2;
	transition: color 0.4s;
	font-weight: 400;
	color: #484848;
}

.todo-list input[name="completed"]:checked + input[name="title"] {
	color: #949494;
	text-decoration: line-through;
}

.todo-list li {
	display: grid;
}

.todo-list li .edit {
	display: block;
	z-index: -1;
}

.todo-list .edit:focus {
	z-index: 1;
	width: calc(100% - 43px);
	padding: 12px 16px;
	margin-left: 43px;
}

input[type="text"]:not(:read-only) {
	position: relative;
	margin: 0;
	width: 100%;
	font-size: 24px;
	font-family: inherit;
	font-weight: inherit;
	line-height: 1.4em;
	color: inherit;
	padding: 6px;
	border: 1px solid #999;
	box-shadow: inset 0 -1px 5px 0 rgba(0, 0, 0, 0.2);
	box-sizing: border-box;
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
}

form[name="newTask"] input[type="text"] {
	padding: 16px 16px 16px 60px;
	height: 65px;
	border: none;
	background: rgba(0, 0, 0, 0.003);
	box-shadow: inset 0 -2px 1px rgba(0,0,0,0.03);
}

main {
	position: relative;
	border-top: 1px solid #e6e6e6;
}

input[name="toggleAll"] {
	appearance: none;
	position: absolute;
	bottom: 100%;
	transform: rotate(90deg);
	font-size: 22px;
	color: #949494;
	padding: 10px 17px;
}

input[name="toggleAll"]:before {
	content: '❯';
}

input[name="toggleAll"]:checked:before {
	color: #484848;
}

.todo-list li input[name="completed"] {
	appearance: none;
	height: 43px;
	width: 43px;
}

.todo-list li input[name="completed"] {
	background-image: url('data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%22http%3A//www.w3.org/2000/svg%22%20width%3D%2240%22%20height%3D%2240%22%20viewBox%3D%22-10%20-18%20100%20135%22%3E%3Ccircle%20cx%3D%2250%22%20cy%3D%2250%22%20r%3D%2250%22%20fill%3D%22none%22%20stroke%3D%22%23949494%22%20stroke-width%3D%223%22/%3E%3C/svg%3E');
	background-repeat: no-repeat;
	background-position: center left;
}

.todo-list li input[name="completed"]:checked {
	background-image: url('data:image/svg+xml;utf8,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%2240%22%20height%3D%2240%22%20viewBox%3D%22-10%20-18%20100%20135%22%3E%3Ccircle%20cx%3D%2250%22%20cy%3D%2250%22%20r%3D%2250%22%20fill%3D%22none%22%20stroke%3D%22%2359A193%22%20stroke-width%3D%223%22%2F%3E%3Cpath%20fill%3D%22%233EA390%22%20d%3D%22M72%2025L42%2071%2027%2056l-4%204%2020%2020%2034-52z%22%2F%3E%3C%2Fsvg%3E');
}

input[name="title"]:read-only {
	border: none;
	outline: none;
}

form.task li {
	display: grid;
	grid-template-columns: min-content 1fr min-content; 
}

.task input[name="completed"] {
	grid-area: 1 / 1 / 2 / 2;
}

.task button[name="destroy"] {
	grid-area: 1 / 3 / 2 / 4;
	padding: 10px;
}

.task input[name="title"]:read-only {
	grid-area: 1 / 2 / 2 / 3;
}

form.task input[name="title"]:not(:read-only) {
	grid-area: 1 / 1 / 2 / 4;
	background: white;
	z-index: 2;
}

.todoapp footer {
	display: flex;
	justify-content: stretch;
	padding: 5px;
	align-items: center;
}

.todoapp footer > * {
	flex-basis: 100px;
}

nav {
	justify-content: center;
	display: flex;
	flex: 1;
}

input[name="clearCompleted"] {
	line-height: 19px;
	text-decoration: none;
	cursor: pointer;
}

input[name="clearCompleted"]:hover {
	text-decoration: underline;
}

nav a {
	color: inherit;
	margin: 3px;
	padding: 3px 7px;
	text-decoration: none;
	border: 1px solid transparent;
	border-radius: 3px;
}

.nav a:hover {
	border-color: #DB7676;
}

.task:not(:hover, :focus-within) button[name="destroy"] {
	opacity: 0;
}