Código HTML:
<!DOCTYPE html>
<html lang="es-ES">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>Grid</title>
<style type="text/css">
.grid {display:-ms-grid; -ms-grid-columns: 1fr 1fr 1fr;}
.grid>*{height:1em; outline:1px solid red;}
.grid>*:nth-child(1){-ms-grid-column: 1;}
.grid>*:nth-child(2){-ms-grid-column: 2;}
.grid>*:nth-child(3){-ms-grid-column: 3;}
</style>
</head>
<body>
<div class="grid">
<div></div>
<div></div>
<div></div>
</div>
</body>
</html>