That’s not really a style that GP supports by default, but something like this should get you started:
.post-navigation {
display: flex;
justify-content: space-between;
padding: 40px 20px;
}
.post-navigation .nav-next {
display: flex;
flex-direction: row-reverse;
text-align: right;
}
.post-navigation .nav-next .gp-icon {
margin-left: 0.6em;
margin-right: 0;
font-size: 20px;
}
.post-navigation .prev:before {
content: "Previous post";
display: block;
}
.nav-previous {
display: flex;
}
.post-navigation .next:before {
content: "Next post";
display: block;
}
.post-navigation a {
font-size: 20px;
}
.post-navigation .nav-previous .gp-icon {
font-size: 20px;
}
.post-navigation > div {
max-width: 48%;
}
This assumes you’re using SVG icons.