[css-forms-1] Add checkmark content for indeterminate checkboxes w3c/csswg-drafts@cf11ed5

Author: triple-underscore

css-forms-ja.html

@@ -159,8 +159,8 @@
 ●●options
 
 spec_title:CSS Gap Decorations Module Level 1
-spec_date:2026-02-26
-trans_update:2026-02-27
+spec_date:2026-03-05
+trans_update:2026-03-06
 	source_checked:
 page_state_key:CSS
 original_url:https://drafts.csswg.org/css-forms-1/
@@ -2714,11 +2714,14 @@ <h3 title="Checkboxes &amp; radios">~checkboxと~radio</h3>
     `content$p: '';
 }
 
-input[type=checkbox]:not([switch], :checked)::checkmark {【 `,^c ？】
+input[type=checkbox]:not([switch], :checked, :indeterminate)::checkmark {【 `,^c ？】
 input[type=radio]:not(:checked)::checkmark {
     `visibility$p: hidden;
 }
 
+input[type=checkbox]:indeterminate::checkmark {
+    `content$p: '\2500' / '';
+}
 input[type=radio] {
     `border-radius$p: 50%;
 }