themes-wordpress/quadrat/sass/blocks/_post-comments.scss

.wp-block-post-comments {

	form {
		input:not([type=submit]):not([type=checkbox]),
		textarea {
			border: none;
			background: var(--wp--custom--color--tertiary);
		}
	}

	// Target certain links within post comments to use the underline treatment.
	.comment-body > p > a,
	.comment-edit-link {
		text-decoration: underline;

		&:hover {
			text-decoration: none;
		}
	}
}