| A progress element should have a nested shadow box with a width specified: | |
| | <progress> | |
| | max="100" | |
| | style="appearance: none;" | |
| | value="70" | |
| | <shadow:root> | |
| | <div> | |
| | useragentpart="-webkit-progress-inner-element" | |
| | <div> | |
| | useragentpart="-webkit-progress-bar" | |
| | <div> | |
| | style="inline-size: 70%;" | |
| | useragentpart="-webkit-progress-value" |