Theming vs. Embedding in NC25+

Steps to reproduce

1. Use e.g. NC25 default theming
2. embed a calendar in another website

Expected behavior

Parameters should allow to match the theming of the TARGET website embedding the calendar, including to override light/dark.

Actual behaviour

Instead, full NC theming is applied, leading to a picture border and e.g. a dark mode rendered calendar within another website (which may not yet allow to switch light/dark).

Example: Website embedding this NC calendar

Calendar app version

4.1.0-rc.1

CalDAV-clients used

–

Browser

106.0.1

Client operating system

Arch Linux

Server operating system

Arch Linuix

Web server

Nginx

Database engine version

MariaDB

PHP engine version

PHP 8.1

Nextcloud version

25.0.0

Updated from an older installed version or fresh install

Updated from an older version

List of activated apps

Enabled:
  - activity: 2.17.0
  - bookmarks: 11.0.4
  - bruteforcesettings: 2.5.0
  - calendar: 4.1.0-rc.1
  - camerarawpreviews: 0.8.0
  - circles: 25.0.0
  - cloud_federation_api: 1.8.0
  - contacts: 5.0.1
  - dav: 1.24.0
  - deck: 1.8.0
  - federatedfilesharing: 1.15.0
  - federation: 1.15.0
  - files: 1.20.1
  - files_mindmap: 0.0.26
  - files_pdfviewer: 2.6.0
  - files_rightclick: 1.4.0
  - files_sharing: 1.17.0
  - files_trashbin: 1.15.0
  - files_versions: 1.18.0
  - groupfolders: 13.0.0
  - logreader: 2.10.0
  - lookup_server_connector: 1.13.0
  - mail: 2.0.3
  - notes: 4.6.0
  - notifications: 2.13.1
  - notify_push: 0.5.0
  - oauth2: 1.13.0
  - password_policy: 1.15.0
  - photos: 2.0.0
  - polls: 4.0.0
  - previewgenerator: 5.1.0
  - privacy: 1.9.0
  - provisioning_api: 1.15.0
  - related_resources: 1.0.2
  - richdocuments: 7.0.0
  - serverinfo: 1.15.0
  - settings: 1.7.0
  - sharebymail: 1.15.0
  - sharerenamer: 3.1.0
  - spreed: 15.0.0
  - suspicious_login: 4.3.0
  - systemtags: 1.15.0
  - text: 3.6.0
  - theming: 2.0.0
  - twofactor_backupcodes: 1.14.0
  - twofactor_email: 2.7.1
  - twofactor_gateway: 0.20.0
  - twofactor_nextcloud_notification: 3.5.0
  - twofactor_totp: 7.0.0
  - twofactor_webauthn: 1.0.0
  - updatenotification: 1.15.0
  - viewer: 1.9.0
  - workflowengine: 2.7.0
Disabled:
  - admin_audit
  - comments: 1.14.0
  - contactsinteraction: 1.1.0
  - dashboard: 7.0.0
  - encryption
  - files_external
  - firstrunwizard: 2.6.0
  - impersonate: 1.11.0
  - nextcloud_announcements: 1.6.0
  - ransomware_protection: 1.13.0
  - recommendations: 0.5.0
  - support: 1.0.1
  - survey_client: 1.5.0
  - tasks: 0.14.5
  - user_ldap
  - user_status: 1.0.0
  - weather_status: 1.0.0

Nextcloud configuration

{
    "system": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "cloud.suevia-ka.de",
            "cloud.seyfarth.de",
            "test.seyfarth.de",
            "cloud.owncube.com"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "25.0.0.18",
        "overwrite.cli.url": "https:\/\/cloud.suevia-ka.de",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 0,
            "dbindex": 4,
            "timeout": 1.5
        },
        "logtimezone": "Europe\/Berlin",
        "trashbin_retention_obligation": "auto,30",
        "versions_retention_obligation": "auto,366",
        "skeletondirectory": "",
        "default_language": "de",
        "default_locale": "de_DE",
        "default_phone_region": "DE",
        "updater.release.channel": "stable",
        "theme": "",
        "loglevel": 2,
        "mail_smtpmode": "smtp",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_sendmailmode": "smtp",
        "mail_smtpport": "25",
        "mail_smtpsecure": "tls",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "simpleSignUpLink.shown": false,
        "twofactor_enforced": "true",
        "twofactor_enforced_groups": [
            "Gruppenadmin",
            "admin"
        ],
        "twofactor_enforced_excluded_groups": [],
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "app_install_overwrite": [
            "files_frommail",
            "camerarawpreviews"
        ],
        "blacklisted_files": [],
        "maintenance": false
    }
}

Web server error log

n/a

Log file

n/a

Browser log

n/a

Additional info

No response

Start by reproducing the linked embedded calendar and compare its rendering with the target website's light and dark themes. Inspect the calendar embed and theming behavior; done means embed parameters can match the target site's theme, including overriding light or dark mode, without applying the full Nextcloud theme.