```html
body {
fontfamily: Arial, sansserif;
margin: 20px;
}
h1 {
textalign: center;
}
.container {
display: flex;
justifycontent: center;
alignitems: center;
flexwrap: wrap;
}
.group {
margin: 20px;
}
.group img {
maxwidth: 300px;
height: auto;
display: block;
margin: 0 auto;
}