Act2.css is attached by default to all Act2 templates.
You can find it in Design Manager at this location:
By default your domain stylesheet is disabled from all your Act2 templates and we strongly recommend keeping it that way. Only Act2.css should be attached:
If you're seeing weird styles in your page, please make also sure there are no other stylesheets attached at the page level. Here is how you can do that:
1 Edit your page
2 Go to Settings > Advanced Options > Stylesheet
3 Make sure the Domain Stylesheets are Disabled or select Use default (recommended) if the domain stylesheets are already disabled from the template (Act2's default setting)
Make sure the Template Stylesheets are Enabled or select Use default (recommended) if Act2.css stylesheet is already attached to the template (Act2's default setting)