:root {
	--root-font-size: 16;
	--main_color: #e27700;
}

#archive-backnumber {
	.posts {
		max-width: 876px;
		margin-left: auto;
		margin-right: auto;
		list-style-type: none;
		padding: 0 1em;
		display: grid;
		grid-template-columns: repeat(3, 1fr);
		gap: 3em;
		margin-top: 3em;
	}
	li {
		background-color: #fff;
		box-shadow: 0.2em 0.2em 0.2em 0.2em rgba(0,0,0,0.25);
	}
	.thumbnail {
		margin: 0;
		img {
			width: 100%;
			height: auto;
		}
	}
	.title {
		margin: 0;
		line-height: 1.4em;
		a {
			padding: 1em;
			display: block;
		}
	}
}