index.html

<!doctype html>
<html>
    <head>
        <meta charset="utf-8">
        <title>SuperVia</title>
        <style>
            body {
                padding: 0;
                margin: 0;
            }
            html, body, #map {
                height: 100%;
                width: 100%;
            }
        </style>
        <link rel="stylesheet" href="https://unpkg.com/leaflet@1.2.0/dist/leaflet.css" integrity="sha512-M2wvCLH6DSRazYeZRIm1JnYyh22purTM+FDB5CsyxtQJYeKq83arPe5wgbNmcFXGqiSH2XR8dT/fJISVA1r/zQ==" crossorigin=""/>
        <script src="https://unpkg.com/leaflet@1.2.0/dist/leaflet.js" integrity="sha512-lInM/apFSqyy1o6s89K4iQUKg6ppXEgsVxT35HbzUupEVRh2Eu9Wdl4tHj7dZO0s1uvplcYGmt3498TtHq+log==" crossorigin=""></script>
    </head>
    <body>
        <p id="loading">Aguarde, carregando...</p>
        <div id="map"></div>
        <script src="https://unpkg.com/axios/dist/axios.min.js"></script>
        <script src="script.js"></script>
    </body>
</html>