JezK
Edit File: style.min.css
.wp-block-post-navigation-link .wp-block-post-navigation-link__arrow-previous{display:inline-block;margin-right:1ch}.wp-block-post-navigation-link .wp-block-post-navigation-link__arrow-previous:not(.is-arrow-chevron){transform:scaleX(1)}.wp-block-post-navigation-link .wp-block-post-navigation-link__arrow-next{display:inline-block;margin-left:1ch}.wp-block-post-navigation-link .wp-block-post-navigation-link__arrow-next:not(.is-arrow-chevron){transform:scaleX(1)}.wp-block-post-navigation-link.has-text-align-left[style*="writing-mode: vertical-lr"],.wp-block-post-navigation-link.has-text-align-right[style*="writing-mode: vertical-rl"]{rotate:180deg}