<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
<style>
#grid {
display: grid;
grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
grid-gap: 5px;
}
#grid > div {
font-size: 30px;
padding: .5em;
color: #ffffff;
background: #1c87c9;
text-align: center;
}
</style>
</head>
<body>
<div id="grid">
<div>1</div>
<div>2</div>
<div>3</div>
<div>4</div>
<div>5</div>
<div>6</div>
<div>7</div>
<div>8</div>
<div>9</div>
</div>
</body>
</html>