Wordpress Twenty Fourteen theme width fit for high resolution monitors

Edit: /wp-content/themes/twentyfourteen/sytle.css

.site-content .entry-header,
.site-content .entry-content,
.site-content .entry-summary,
.site-content .entry-meta, .page-content {
 /* Original max-width: 474px */
 max-width: 80%;
}