On these screens, sometimes the icons will be `$sdg-icon-min-width`
wide, but the margins were not taking this into account.
We can use CSS `max` function to set minimum margins just like we set
minimum width. However, there are two things to take into account:
* LibSass does not support these functions as it tries to use Sass own
functionst at compile time, so we need to hack them writing `Max()`
(which works in CSS because it is not case sensitive)
* Not all browsers support it (90% at the time of writing), so we write
the rules twice (the first time for browsers not supporting it); we
could use `@supports` but then we would have to overwrite some of the
rules in the `.sdg-goals-index .sdg-goal-list` selector using
`!important` or adding a `@supports` clause there as well
cdfa23fc6f