Hi Martin. If you allow...
I don't think that the use of this code is advisable.
.sppb-addon-title{
font-family: "Raleway" !important;
}
Each unnecessary code is garbage which worsens performance.
As Rashida noted correctly - it getting priority from addon settings. But instead of using additional code, you just need to delete font-family setting in the addon. (Tip - never use font-family settings in addons, this connects an additional font to your site, which is bad for performance)
If you want to connect the same font to all elements on the site, this record works, but it does not make sense
body, p, h1,h2,h3,h4 {font-family: 'Raleway';}
Better use such a record that is quite enough.
body {font-family: 'Raleway', sans-serif;}
Always add sans-serif or serif . This uploads a font without serif or with serif from the user system if for some reason the font of the site does not load. This will make your site looking normally in an emergency with a font.
And yes, if you will use custom.css file it should works. If it does not work, then the reason is in the code that you use. The browser code inspector will always help find the reason