I have a long string, without whitespace, and a I want to place it in a div, such that

1. It fills the div as much as possible, without overflowing.
2. It uses the same amount of characters on each line (except the last, which line may be less).

The div is a responsive div, with width 90vw and height 84vh.

The HTML is:

<div class = "content"><p><code>Some-very-large-string-without-white-space"</code></p></div>

Scaling the font so it just fits is easy with a bit of JavaScript:

function font_fiddle (selection) {
    let element  = document . querySelector (selection)

    let fontSize = element . clientHeight

    if (!element . innerHTML . length) {
        return;
    }

    element . style . fontSize = fontSize + 'px';
    while (element . scrollHeight > element . clientHeight && fontSize > 0) {
        element . style . fontSize  = -- fontSize + 'px';
    }
}

font_fiddle (".content") is called when the document loads, and when the window resizes. This parts works well.

The CSS for the code element is:

code {
    word-break: break-all;
    color: lightgreen;
    background: black;
    font-style: initial;
    font-family: 'Source Code Pro', monospace;
    font-size: 95%;
}

Due to the monospace font, and the word-break: break-all, I would expect all lines (with the exception of the last) to have the same number of characters, and to have a straight right "edge". And this would be the case if the string contains just letters and digits. But my string doesn't, and this leads to some lines being a one or a few characters shorter than possible:

Changing the CSS to word-break: break-word; has some effect, but we're still left with a jagged right edge:

Is there a way to get every line contain the same amount of characters, regardless of what those characters are?

This all is with Firefox on MacOS.