css-toggle.js

function set_stylesheet_disable(val) {
    for (let i = 0; i < document.styleSheets.length; i++) {
        document.styleSheets.item(i).disabled = val;
    }
}

function disable_stylesheets_hold() {
    document.addEventListener("keydown", function (e) {
        if (e.key === "Escape") {
            set_stylesheet_disable(true);
        }
    });

    document.addEventListener("keyup", function (e) {
        if (e.key === "Escape") {
            set_stylesheet_disable(false);
        }
    });
}

function disable_stylesheets_toggle() {
    document.addEventListener("keyup", function (e) {
        if (e.key === "Escape" && document.styleSheets.length) {
            set_stylesheet_disable(!document.styleSheets.item(0).disabled);
        }
    });
}