On desktop, "More options" and the pencil icon open the event editor in a fixed, narrow window, about 600 px wide, even on a large monitor. The description box grows to about 5 lines and then scrolls, and there is no way to enlarge the window. Writing an agenda, meeting notes, directions or any longer text means working inside a small box in the middle of an empty screen.

Proposal
1. A maximize / expand button in the editor header that switches it to full screen (or a full-page view) and back.
2. A setting to always open the editor maximized.
3. In the maximized view, use the space: a two-column layout (details on one side, description on the other) and a description field that fills the available height.
4. Nice to have: open an event in its own tab or window.

Why it matters
- Google Calendar's "More options" opens a full-page editor, and people coming from Google expect the same.
- The editor already switches to full screen on small screens, so the full-screen layout exists; it just isn't available on desktop.
- Longer, richer descriptions (see the rich-text request) need room to be readable and editable.

Related: https://protonmail.uservoice.com/forums/284483-proton-mail-calendar/suggestions/42106489-add-rich-text-editor-and-increase-character-limit