Add input groups using subgrid where applicable

[Lenni009]

Subgrid is currently still not supported in Chrome -> blocker
Track the status on MDN: https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_grid_layout/Subgrid

[Lenni009]

Subgrid class:

.subgrid {
	display: grid;
	grid-template-columns: subgrid;
	border: 1px solid red;
	grid-column: 1/span 2;
	gap: 0;
}

gap can also be unset or inherit. Basically anything works.

[Lenni009]

The current Chrome update supports subgrid. There is no further blocker to this issue.