Ciao,

As always there are a few methods to achieve this.

Quick Idea 01:

1. Create a new Custom Module (native) with button inside, just use bootstrap classes (screenshot) or your design concept.
2. Then publish that module on "logo" position.
3. Then use following Custom CSS (example):

#sp-logo .sp-module {display: none;}
@media screen and (max-width: 680px) {
#sp-logo .sp-module {display: inline-flex;}
}

Desktop & tablet - Hide button, Show on Mobile.

Thanks but I'm obviously doing something wrong. If I don't insert the CSS I see the button on both desktop and mobile but under the logo section; if I insert the CSS I don't see the button on mobile either.

probably becuase, I ate "d" in below word, I had to be hungry ;)

width: 680px

1st line was/is fully OK, it should hide it. All works on my demo site. Evidence.

It works great. Thanks. Now if you could also tell me how to change the color of the button I would be grateful. I can't find the right CSS. I thought it was here: "‎/templates/luxevista/css/presets/preset1.css" in the "luxevista" template. But apparently it is not.

Or here: "‎/templates/luxevista/css/bootstrap.min.css" in the "luxevista" template. But not even that.

I was honestly surprised by this question, I thought you were professionally involved in web development. If not, please check:

• https://getbootstrap.com/docs/5.0/components/buttons/
• Yes, You can override any bg color using Custom CSS.

Default BT style for btn-info class used in my example

.btn-info {
  color: #000;
  background-color: #0dcaf0;
  border-color: #0dcaf0;
}

.btn-info:hover {
  color:#000;
  background-color:#31d2f2;
  border-color:#25cff2
}

There is, but better use Custom CSS fort custom color or just ready class names. Less stress ;)

Then use custom.css file, and do not edit other template .css files.

I am truly sorry to have disappointed you. On the other hand, I can do many things. For example, I am very good at recognizing unsurpassed availability and professionalism. Now everything is ok. Thank you very much.