at the top of each page, you'll want to add this meta tag:
<meta name="viewport" content="width=device-width, initial-scale=1">
and add this css, either to the bottom of the <style></style>
block or making the changes to each css item
*, *:before, *:after {
vertical-align: top;
}
.col_1of2, .col_2of2 {
border: none;
display: inline-block;
float: none;
}
@media (max-width: 480) {
.col_1of2, .col_2of2 {
display: block;
}
}