@klox77: 900px is too small. When you make 900px you need to adjust a lot. So, add in the following CSS in “Appearance => Theme Options => Custom CSS” box.
@media screen and (min-width: 1060px) {
.site {
margin: 20px auto;
width: 900px;
}
#primary {
width: 500px;
}
.page-links,
.widget,
blockquote,
.site-content article,
.site-content .site-navigation,
#infinite-handle,
.comments-title, #reply-title,
#respond {
margin-bottom: 30px;
}
#homepage-message {
margin-top: 30px;
}
article.sticky .featured-post,
.page-header,
p,
.featured-image,
.entry-content table,
.comment-content table,
.widget.widget_catcheverest_social_widget,
#content .searchform {
margin-bottom: 20px;
}
#header-right .widget,
.entry-header,
article.format-aside .entry-title,
.comments-area article header {
margin-bottom: 20px;
}
.page .entry-header,
.widget-title,
#header-right .widget.widget_catcheverest_social_widget {
margin-bottom: 10px;
}
.container {
padding: 0 30px;
}
#site-logo,
#hgroup,
#header-right,
#supplementary,
#main {
padding-top: 30px;
}
#hgroup-wrap,
.hentry,
.comments-area article {
padding-bottom: 30px;
}
#site-generator .site-info {
padding: 20px 0;
}
#header-menu ul.menu a,
#colophon #access-footer ul.menu a {
padding: 0 15px;
}
.entry-header .entry-title {
padding-bottom: 0;
}
}