Title modification by child theme and css rule

Hi all,

I’m working on this website https://www.manlioajovalasit.com and to set some modification by css I created a child theme. I would like to change the appearance of the title and setting the font lowercase and thinner.

I tried to use the class .site-title { } to make it and it worked for some modification. I have set up the rule like that:

.site-title {margin: 0; padding: 2px 0 8px; font-size: 64px; line-height: 64px; font-weight: 100; text-transform: none; word-spacing: -16px;}

And it worked well because it changed the title from uppercase to lowercase but it seems the other properties do not work. I tried several times but no one of them, expecially font-weight, worked.

The only two properties seems working are word-spacing and text-transformation.
What should I do? I tried also setting !important but it did not work.

I would like to know also if how can I set a <span> to modify just one of the two words which compose the title.

Thanks in advance

The page I need help with: [log in to see the link]