Make my brand look consistent everywhere (documents, client portal, and app)

I want to set up my business branding once so everything my clients see matches my brand automatically. When I upload my logo and choose my brand colors and fonts, I want TalleFlow to use them across: The documents I create and send (including inside the editor, so I can pick my brand colors fast) The client portal experience (buttons, headers, links, etc.) The app UI (so it still feels like my business) I should be able to: Upload my logo (and ideally have a light and dark version) Choose primary and secondary colors (plus a few accent colors) Pick heading and body fonts (with safe fallbacks) Preview what it will look like before saving Create multiple themes and choose a default theme for my business Most importantly, once I send a document to a client, it should not change later if I update my brand settings.