Main Content Area Width

I am trying to adjust the width of the main content area so that it doesn’t have a bunch of empty wasted white space on each side of the main content. I found the following in the style.css page and saw other posts that people changed the width from 474 to 100% and it fixed it, but that didn’t work for me. Is there something else I need to change or do?

* 6.0 Content
* —————————————————————————–
*/

.content-area {
padding-top: 48px;
}

.hentry {
margin: 0 auto 48px;
max-width: 472px;
}

.site-content .entry-header,
.site-content .entry-content,
.site-content .entry-summary,
.site-content .entry-meta,
.page-content {
margin: 0 auto;
max-width: 100%;
}

.page-content {
margin-bottom: 48px;
}