Can you identify telepathically received messages sent through spells like Sending as magical via Detect Magic?

An enemy casts Sending to communicate with a player from far away. In this example, the player character doesn’t know anything about the Sending spell and he might think he is just hearing voices or going crazy.

Another player casts Detect Magic to scan the area. Can this player detect the presence of the telepathic message inside the first players head via Detect Magic as an evocation spell.

How does Counterspell interact with the Detect Magic spell?

  1. If a character casts Counterspell against Detect Magic as it is being cast, will the caster of Detect Magic know this, or will they think there is no magic present for the duration of the spell? Does the caster of Detect Magic know it’s been counterspelled?

  2. RAW I assume the answer is no, but if Detect Magic is already cast and active, does Counterspell have any effect?

Tor Browser: Could a website or ISP detect modification to DOM done by users if Javascript is disabled?

I have Tor Browser (which is basically Firefox ESR) on "Safest" setting (Javascript disabled). We’re generally scolded about using extensions in it, as they can alter web traffic patterns to or from your browser, adding another fingerprinting vector by distinguishing you from other Tor Browser users.

If JS is turned off even in vanilla Firefox, and I apply modifications to the DOM (like CSS mods, zooming in etc.) after the website has finished loading, I can’t see how a website or ISP could detect what the user is doing in the DOM.

I know if you, for example, hide an element in CSS before it is fully loaded (such as the sidebar), the browser may skip downloading resources (such as icons) associated with the element. This would distinguish your web traffic patterns from other users. That’s why I wait till the page is fully loaded. I’m also careful to not trigger CSS media queries which can be set up to connect to a remote URL if triggered (or remove them first if they will be triggered).

I think the above should be enough to avoid distinguishing myself by my web traffic. Do you see any way I could be distinguished with only CSS & HTML?