Hi Prisca,
That Extra White Space is caused by padding on #cir-content-wrapper which is below #cir-banner. Override #cir-content-wrapper’s padding from style.css of child theme. Or if you want to use/keep directly, then please use the following css:
#cir-content-wrapper {
padding: 0;
}
We hope this will be helpful to you, if not then please let us know.
Thanks