Reply To: Logo and site title lined up

@Susie: That’s not possible with custom css. So, I suggest you to add those text in the image itself and just add logo and disable site title and tagline.

Or you can float logo and title both to the left. For this, you can just add the following css in “Appearance => Customize => Theme Options => Custom CSS Options” box:

#site-logo,
.logo-left #site-header {
    display: inline;
    float: left;
    width: auto;
}