Does it look better with View/Density set to Relaxed? You might also need to change View/Font Size.

It is slightly better when Density is set to Relaxed. How can this be set to even higher?

See https://support.mozilla.org/en-US/questions/1423577#answer-1602941

https://support.mozilla.org/en-US/questions/1423577#answer-1602941

The above link gives the line height code for Table View. For Cards View, use this code:

/* threads pane card height */
.thread-card-container{
     height: 60px !important;
}

The solution in post is taking effect only in the table view. Is there any way to set height and font-size in cards view?

Add this line to the above code to set the font size:

font-size: 18px !important;

It takes effect only when I remove '[is="thread-row"]' tr selection.

This is my userChrome.css

@namespace html url("http://www.w3.org/1999/xhtml");

/* threads pane line height */ html|tr {

  font-size: 24px !important;
  height: 95px !important; }

Edit: As of 2023, layout.css.devPixelsPerPx is no longer supported starting with version 115. Anything other than the default -1.0 may cause problems. See https://support.mozilla.org/en-US/kb/thunderbird-115-supernova-faq#w_why-are-the-fonts-still-too-large-or-too-small-after-i-changed-the-density-and-font-size

Finally figured it out. The CSS selector is "thread-card"

The below CSS in userChrome.css with devPixelsPerPx set to 0.7 ( in config editor ) did the trick for me. The below is what suits in my display. For others, it will vary.

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); @namespace html url("http://www.w3.org/1999/xhtml");

/* threads pane line height */ html|tr[is="thread-card"] {

  font-size: 24px !important;
  height: 125px !important;

}

/* Global UI font */

• { font-size: 24px !important;

}

To make the sender bold in card view:

/* bold sender in card view */
.thread-card-container{
	font-weight: bold !important;
}