Add font size by variable, and check excerpt empty

[zkmark]

Description

Describe your feature request.

Add font size by variable, and check excerpt empty

References

In this part you should use a css variable
https://github.com/tomusborne/generatepress/blob/master/assets/css/all.css#L629

For example, the one that comes with WordPress by default
font-size: var(--wp--preset--font-size--normal);

Since it can't be changed from the css editor even if I use !important

--
In this part, you should ask if the_excerpt() exists, since it generates empty space when you add the excerpt value to 0

https://github.com/tomusborne/generatepress/blob/master/content.php#L69

<?php if (get_the_excerpt()): ?>
<div class="entry-summary"<?php echo $itemprop; // phpcs:ignore -- No escaping needed. ?>>
<?php the_excerpt(); ?>
</div>
<?php endif ?>