“Add to cart” button not working on Safari or iOS
Safari blocks third-party cookies, and while your site reaches Fontdue across a fontdue.com address, the cart cookie counts as third-party. The fix is a custom domain – serving Fontdue from a subdomain of your own site makes the cookie first-party. Contact us to set one up.
Glyphs float below baseline in the Character Viewer in Firefox
Try increasing the ascender value in the hhea table. Sometimes Firefox has issues with fonts with a small ascender value. For example, this font11
with an ascender value of 740, Firefox seems to force the ascender to be bigger, making the font’s bounding box bigger than expected (so pushing it down below the bounding box lines Fontdue draws).
After increasing the ascender value to 800, the issue is fixed.22
Fonts have multiple ways to define vertical metrics (hhea, typo, and win). Fontdue attempts to harmonize the vertical metrics across different browser environments (in the webfonts served for foundry sites) by setting the CSS @font-face values ascent-override, descent-override and line-gap-override to match the values in the hhea table (since Safari looks at the hhea metrics, but does not support the override properties). This normally takes care of discrepancies in the vertical metrics, but the browser engines seem to take more things into consideration beyond just these values.
We recommend ensuring the hhea and typo values are in sync for your customers’ self-hosted webfonts.