JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//ajax.googleapis.com/ajax/libs/jqueryui/1.11.1/jquery-ui.min.js"></script>
<div class="h-line guide" style="top: 100px"></div>
<div class="h-line guide" style="top: 400px"></div>
<div class="v-line guide" style="left: 80px"></div>
<div class="v-line guide" style="left: 400px"></div>

<div class="block"></div>

CSS

.h-line {
    background-color: #000;
    width: 10000px;
    height: 1px;
    overflow: hidden;
    position: absolute;
    left: 0;
}

.v-line {
    background-color: #000;
    width: 1px;
    height: 10000px;
    overflow: hidden;
    position: absolute;
    top: 0;
}

.block {
    width: 150px;
    height: 150px;
    background-color: red;
    position: absolute;
    left: 80px;
    top: 100px;
}

JavaScript

$(".block").draggable(
    {
        snap: ".guide",
        snapTolerance: 10,
        //grid: [10,10],
        start: function(event, ui) {
            $(".h-line").css("display", "block");
        },
        stop: function( event, ui) {
            $(".h-line").css("display", "none");
        }
    });