these are some css rules to make tasks.google.com/embed/?origin=https://mail.google.com accessible from browsers without Gmail integration.
- sign in with your google account.
- install User JavaScript and CSS extention for chrome browser
- open it then add a new rule for tasks.google.com
- copy and paste css/javascript files content to the appropriate text field. Save it.
- browse to https://tasks.google.com/embed/?origin=https://mail.google.com. the parameter ?origin is very important and missing it will cause a 404 server error.
- install Open-as-Popup extention for chrome browser. this will make your tab as a native mac/windows/linux application.
- enjoy!