fori,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style>
body{
margin: 0;
overflow: hidden;
display: flex;
}
.wrapper{
width: 100vw;
height: 100vh;
}
.Rectangle{
width: 100vw;
height: 20vh;
background: green;
transform: translateY(44vh);
}
.But{
height: 20vh;
text-align: center;
font-size: 10vmin;
transform: translateY(44vh);
animation: test 5s ease-in-out infinite;
}
h1{
position: fixed;
height: 1px;
width: 100vw;
top: 50%;
background-color: #FFFF00;
}
@keyframes test {
50% {
font-size: 40vmin;
}
}
</style>
</head>
<body>
<div class="wrapper">
<div class ="Rectangle"></div>
<div class="But">Выйти</div>
</div><h1></h1>
</body>
</html>