You can try adding this code to your responsive section at the bottom of your css (in the mobile area around line 4181 ) –
.header-image .site-header .widget-area {
padding: 0;
}
This will override the code that is active on the desktop part of the css which looks like this –
.header-image .site-header .widget-area {
padding: 40px 0;
}
Add the code at the top under line 4181. The section should look like this –
/* iPhones (portrait and landscape)
--------------------------------------------- */
@media only screen and (max-width: 767px) {
Let me know if that helps.