use css short forms: padding-inline, margin-inline

There's some css in olivero which could be improved.
At the same, I don't want to dive deeply into all the design circumstances so I've resisted doing so.

However, this is an easy improvement with no drawbacks:

Do you agree if i replace and MR such constructs:

padding-inline-start: 0;
padding-inline-end: 0;

with their shorthand ?

padding-inline: 0;