Test link(s): [test](https://w3c.github.io/i18n-tests/exploratory/index.html?text=%3Cp%20id%3D%22space%22%3EMM%E3%82%A8%E3%82%A8%E3%82%A8mm%E3%82%A8%E3%82%A8%E3%82%A824%E3%82%A8%E3%82%A8%E3%82%A8%3C%2Fp%3E%0A%3Cp%20id%3D%22control%22%3EMM%E3%82%A8%E3%82%A8%E3%82%A8mm%E3%82%A8%E3%82%A8%E3%82%A824%E3%82%A8%E3%82%A8%E3%82%A8%3C%2Fp%3E%0A&css=.test%20%23space%20%7B%20text-autospace%3A%20ideograph-alpha%20ideograph-numeric%3B%20%20%7D&lang=ja&fontSize=36&width=622&height=230&a=text-autospace%3A%20ideograph-alpha%20ideograph-numeric%3B%20creates%20a%20thin%20gap%20between%20runs%20of%20katakana%20and%20both%20romaji%20letters%20and%20digits%20in%20Japanese&i=Test%20passes%20if%20a%20small%20gap%20appears%20between%20Latin%20text%20and%20digits%20and%20katakana%20characters%20in%20the%20top%20line.%20The%20bottom%20paragraph%20has%20no%20autospace%20applied%2C%20and%20so%20there%20should%20be%20no%20gaps.) Results: - **Gecko:** ❌ *Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:136.0) Gecko/20100101 Firefox/136.0* - **Blink:** ❌ *Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36* - **Webkit:** ✅ *Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.4 Safari/605.1.15* Related tests: [Interactive test results: Text spacing](https://www.w3.org/International/i18n-tests/results/int-letter-spacing.html)