main.css

header, .sidebar-one, .sidebar-two, .content, footer{
	border: 1px solid lightblue;
}

@media(min-width: 400px) {
	.hg-body{
		display: grid;
		grid-template-columns: 20% 1fr 20%;
		grid-gap: 10px;
		height: 100vh;

	}

	ul li {
		display: block;
	}

	header, footer {
		font-size: 50px;
	}
}