Can’t get ride of space between title and support title

Hi,

I’m having a problem with a blank space that appears in the header between the site title and the support text just under it. This space appears only on small screen resolution : on mobile device or on desktop when resizing the browser window to be smaller.

While trying to prevent this from happening (tried to set the padding, margin but nothing worked) i made a color code for each area of the header using custom css :

header#masthead =blue
.site-title = yellow
.support-text = red
.logo = green

Now back to my problem. When going to my website (http://vitrailkb.com) on a desktop pc, everything’s fine, there’s no spacing between site title and support text. When resizing the browser a bit, left and right blue areas « disappear » but it’s still fine. When resizing it even more, a blue space appears between title and support title. That’s what i would like to get ride of.

I tried to make the support-text disappears on smaller resolutions / mobile devices (which would be a fair workaround) : at first it disappear when resizing, but it displays again when resizing more (the resolution where blue space appears between title and support title is the same resolution where support-text display back).

I’m using Vantage theme (premium) and site origine page builder + custom css.

Can you help me with this ?

Thank you !