Fullscreen Toolbar Shortcut for Kiwi mobile browser

kiwi_fullscreen_toolbar_shortcut.js

// "create new action" in toolbar shortcut settings
// give your shortcut a name and paste following code
// add this in the code section and make sure this option
// is selected to run when the shortcut key is pressed.

// Made by ksgwxfan (with some help from search results/how-to).
// Modify/use how you'd like as long as it is for personal use
// or with good or legal intentions.
// For CSS, use inline elements and use Object.assign for
// attribute creation. Otherwise it may not work right.

function hidebar() {
    _bar.style.display = "none";
}

function exitfullscreen() {
    document.exitFullscreen();
    hidebar();
}

function gofullscreen() {
    document.body.requestFullscreen({"navigationUI": "hide"})
		      .then(
            zxcv => {
                // these lines are to ensure scrolling is enabled as applicable
                document.body.style.overflowY = "auto";
                document.body.style.overflowX = "auto";
            }
        );
    hidebar();
}

// create the option bar element
if ("_bar" in window == false) {
    // create fullscreen css rules through style element
    let rule = document.createElement("style");

    // this rule is needed to prevent the web page from being blacked out
    Object.assign(rule, {type: "text/css"});
	   rule.innerText = "body::backdrop {background:transparent}";

    // give this rule to the body element
    document.body.appendChild(rule);

    // the element itself
    _bar = document.createElement("div");

    // set css of the bar
    Object.assign(
        _bar,
        {
            style: [
                "display:flex",
                "position:fixed",
                "top:0",
                "left:0",
                "background-color:white",
                "border-top:2px solid black",
                "border-bottom:2px solid black",
                "width:100%",
                "padding:2vmin",
                "z-index:99999999",
            ].join(";"),
        }
    );

    // bar button style
    let btnstyle = document.createElement("style");
    Object.assign(btnstyle, {type: "text/css"});
    btnstyle.innerText = `button {font-size:3vmin;margin:1vmin;padding:3vmin;}`;
    _bar.appendChild(btnstyle);


    // *********** Add Button Elements Here ***********

    // Create Close Button
    let closebtn = document.createElement("button");
    Object.assign(closebtn, {id: "closebar"});
    closebtn.onclick = hidebar;
    closebtn.innerText = "X";

    // add close button to bar
    _bar.appendChild(closebtn);

    // Fullscreen button
    let fullbtn = document.createElement("button");
    Object.assign(fullbtn, {id: "gofull", onclick: gofullscreen});
    fullbtn.innerText = "Go Fullscreen";

    // add full screen button to the bar
    _bar.appendChild(fullbtn);

    // ************************************************

    // add option bar to body
    document.body.appendChild(_bar);

}

// since bar has already been created, just reveal it
else {
    // Display bar if it exists
    _bar.style.display = "block";
}