lab1.css

* {
	-webkit-box-sizing: border-box;
			box-sizing: border-box;
	margin: 5px 0 0 0;
	padding: 0;
	
	font-size: 18px;
	
	text-align: center;
}
span,
button {
	padding: 4px;
}

div {
	display: inline-block;
}

@media (max-width: 600px) {
	div {
		display: flex;
		-webkit-justify-content: center;
		        justify-content: center;
		
	}
}

[type="radio"] {
	display: none;
}

label {
	padding: 5px 14px;
	border: 1px solid #000;
	cursor: pointer;
}

input:checked + label {
	background-color: #000;
	color: #fff;
}

#lines, 
#circle {
	display: none;
}