The initial pop red color doesn't have a good contrast and the transparent background from the cancel button makes it harder to read when has a element behind the button

• Main title is white we cant read it
• There is a broken image after the menu
• some of the markup can be made with md instead html
• would be nice to talk about the project before get into technologies

You can define the icons when the user add your app at the homescreen:

https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariWebContent/ConfiguringWebApplications/ConfiguringWebApplications.html

There is a reason to use different html tags for the save interactions, if not you can keep both as a button:

<a href="#" class="button cancel cancel_voice">Cancel</a><button class="button accept_voice">Yes</button>

Add a manifest json and service worker to make the app installable:

https://web.dev/add-manifest/

Some parts of the code has empty p and ul, avoid add those items if they are not necessary

line 40:
<p></p>