Спасибо разобрался -
для тех кому нужно решение
<!DOCTYPE html>
<html lang="ru">
<head>
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js" integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>
<meta charset="UTF-8">
<title>test</title>
</head>
<style>
*{
}
body{
margin: 0;
background: #FFF4F2;
color:#2E2E2E;
font-family: Verdana , Arial;
}
#ContainerModBody{
background: #4800FF;
width: 100%;
height: 100vh;
position: fixed;
opacity: .15;
display: none;
}
#modalCont{
z-index: 5;
display: none;
width: 800px;
height: 600px;
background: #E8F3EC;
border-radius: 20px;
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50% , -50%);
}
#close{
padding-right: 15px;
float: right;
font-size: 600%;
cursor: pointer;
}
#modalTextH1{
font-family: Microsoft JhengHei Light;
margin: 30px;
text-align: center;
font-size: 350%;
}
#textModal{
padding-left: 7%;
padding-right: 6%;
font-size: 109%;
word-spacing: 2px;
line-height: 1.6;
}
</style>
<body>
<div id="ContainerModBody"></div>
<div id="modalCont" >
<span id="close">×</span>
<p id="modalTextH1">Модальне окно</p>
<p id="textModal">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Hic fugiat iusto aliquid nemo reiciendis, libero id dolor, nisi nobis sapiente error, debitis accusamus impedit repellat eveniet tenetur repellendus adipisci, labore maiores voluptatum delectus dolorum temporibus! Maxime a, aspernatur cupiditate sed minima qui ipsum officiis voluptate distinctio quos nesciunt alias eius eaque laudantium quia iusto quod. Alias veniam officia dolor fugiat fuga autem, commodi doloremque obcaecati quas officiis veritatis dolore possimus molestiae quibusdam voluptate sunt consequuntur delectus! Ipsa harum molestias, molestiae nam libero officiis dignissimos praesentium doloremque nulla distinctio earum est blanditiis ullam nesciunt ipsam, minus, dolorem maiores, voluptates animi veniam id ut. Laudantium reprehenderit vero, veniam fuga nulla aliquam harum laboriosam. Tenetur officia enim vero vitae et eveniet consectetur cum culpa aperiam repellat beatae velit, mollitia, nemo incidunt, quia inventore!</p>
</div>
<button id="myBtm" style="height: 100px;">Open</button>
</body>
</html>
<script>
var myBtm = document.getElementById('myBtm');
var modalCont = document.getElementById('modalCont');
var ContainerModBody = document.getElementById('ContainerModBody');
var close = document.getElementById('close');
myBtm.addEventListener('click' , function () {
modalCont.style.display = 'block';
ContainerModBody.style.display = 'block';
});
setTimeout(function () {
modalCont.style.display = 'block';
ContainerModBody.style.display = 'block';
}, 800);
close.addEventListener('click' , function () {
modalCont.style.display = '';
ContainerModBody.style.display = '';
});
ContainerModBody.addEventListener('click' , function () {
ContainerModBody.style.display = '';
modalCont.style.display = '';
});
</script>
