Update responsive layout

[cairocoder01]

When viewing the current dashboard on a mobile device, you only see the Active Contacts tiles and might not ever scroll down to see more. Most phones have enough screen space to show more tiles than that. This collapses the tiles a bit vertically and updates the grid layout to be more responsive and adapt to different screen sizes.

This does make minimal use of container queries, which aren't 100% available but are about 80% on CanIUse. These solely provide enhancements that will fallback to the current view anyways, so users with older browsers will get the same experience as before.

See below screenshots for before/after comparisons at different resolutions (breakpoints used by Chrome DevTools responsive view).

Note: Github can't vertical align tables, so I recommend opening dev tools and creating this style so you can do a better side-by-side comparison:

table td {
    vertical-align: top;
}

Resolution	Current/Old	New/Updated
320px
425px
768px
1024px
1440px

[corsacca]

Awesome work @cairocoder01! Love it.