try removing the width around line 1339 .hf-bg .wrap –
.hf-bg .wrap {
margin: 0 auto;
overflow: hidden;
padding: 40px 0 0;
text-align: left;
}
You won’t need to add a width since the .wrap (which is in the other part of the css) already handles it. It will automatically adjust to the browser.
Then look around line 3978 and add this .hf-bg .wrap, to the list so your content won’t show up too close to the edge of the screen. This will put some space in between everything on the sides –
.site-header,
.nav-primary .wrap,
.nav-secondary .wrap,
.slider .wrap,
.welcome .wrap,
.hf-bg .wrap,
.home-feature-bg .wrap,
.home-feature-bg-alt .wrap,
.home-feature-bg-dark .wrap,
.footer-widgets .wrap {
width: 90%;
}