JSFiddle - React, Tailwind, and code Playground

HTML

<div id="TheSafeZone" class="zone">
    <p>The Safe Zone</p>
    <input type="text" />
    <br/>
    <input type="text" />
    <br/>
    <input type="text" />
</div>
<div id="TheDangerZone" class="zone">
    <p>The Danger Zone</p>
    <input type="text" />
    <br/>
    <input type="text" />
    <br/>
    <input type="text" />
</div>

CSS

.zone{
    display:inline-block;
    padding:10px;
    margin:10px;
}

#TheSafeZone {
    background-color:#AEA;
    border:2px solid #0A0;
}
#TheDangerZone {
    background-color:#EAA;
    border:2px solid #A00;
}

JavaScript

var timeoutID;

$("#TheSafeZone input").focus(function () {
    if (timeoutID) {
        clearTimeout(timeoutID);
        timeoutID = null;
    }
});

$("#TheSafeZone input").blur(function () {
    releaseTheHounds();
});

function releaseTheHounds() {
    timeoutID = setTimeout(function () {
            alert("You're all going to die down here");
    }, 1);
}