Hello.

I can't seem to get the H1 on the Single Portfolio pages to be responsive. The text is very large.

I have tried adding CSS to the customiser but still doesn't work. Added the Related URL as an example:

@media only screen and (max-width: 690px)
body.single-portfolio .row .col.section-title.span_12 h1 {
    width: 280px;
    margin: 0 auto;
    line-height: 30px;
    font-size: 24px;
}

I've spotted my mistake. Missing curly brackets  on the media screen size. All working now.