three.js/index.html

<style>
* {
    box-sizing: border-box;
   -moz-box-sizing: border-box;
}
body {
    margin: 0;
    font-family: sans-serif;
    font-weight: bold;
    color: white;
    background-color: blue;
}
#page {
    width: 100vw;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-content: center;
    align-items: center;
}
#page>h1 {
    font-size: 5vh;
    flex: 1 1 auto;
    text-align: center;
}
</style>
<div id="page">
<h1>...coming soon...</h1>
</div>