Hi,
The Twenty Twenty-One theme adds specific fonts for non-latin languages, “Helvetica Neue” for Greek in your case. To override it, you can add the following CSS code in the Customizer > Additional CSS panel:
body, input, textarea, button, .button, .faux-button, .wp-block-button__link, .wp-block-file__button, .has-drop-cap:not(:focus)::first-letter, .entry-content .wp-block-archives, .entry-content .wp-block-categories, .entry-content .wp-block-cover-image, .entry-content .wp-block-latest-comments, .entry-content .wp-block-latest-posts, .entry-content .wp-block-pullquote, .entry-content .wp-block-quote.is-large, .entry-content .wp-block-quote.is-style-large, .entry-content .wp-block-archives *, .entry-content .wp-block-categories *, .entry-content .wp-block-latest-posts *, .entry-content .wp-block-latest-comments *, .entry-content p, .entry-content ol, .entry-content ul, .entry-content dl, .entry-content dt, .entry-content cite, .entry-content figcaption, .entry-content .wp-caption-text, .comment-content p, .comment-content ol, .comment-content ul, .comment-content dl, .comment-content dt, .comment-content cite, .comment-content figcaption, .comment-content .wp-caption-text, .widget_text p, .widget_text ol, .widget_text ul, .widget_text dl, .widget_text dt, .widget-content .rssSummary, .widget-content cite, .widget-content figcaption, .widget-content .wp-caption-text {
font-family: var(--font-base);
}
Hope that helps,
Yann
