First Steps Grav + Hola Theme: How to resize custom logo?

Hi there,
I just installed GRAV yesterday for the first time and want to make a new website for a yoga academy. I decided to use to "Hola"-Theme. I already managed to change the logo to my own custom logo..... but the size is veeeery small. Can anybody tell me how I can change the size? The yaml-file looks like that:

YAMLCopy

enabled: true
custom_logo:
  user/themes/hola/images/logo/logo.png:
    name: logo.png
    type: image/png
    size: 5238
    path: user/themes/hola/images/logo/logo.png

You can use the Custom CSS plugin and just add some CSS to change the logo as needed.

Something like
.header-logo,
.header-logo img {
max-height: 200px;
max-width: 200px;
height: 200px;
width: 200px;
}

Thank you! Yes I knew that option with the custom CSS, but with that I would simply override the YAML. Question for me is what is the "size"-value there in the YAML for the custom_logo? Because nothing changes when I comment that line out! I don't see any change when doing so.

If I look in user/themes/hola/css/main.css I see the CSS code for the logo. I don't see anything in the yaml files for it.