Hello There,
Thanks for writing in! I have inspected the page and it turns out that you have inserted a series of recent posts shortcodes in the text element. Please keep in mind that a new line and line breaks present on the text element will be converted into p and br tags. To resolve your issue, please add the following CSS code in the X > Launch > Theme Options > Global CSS (http://prntscr.com/evui3r) or in the customizer, Appearance > Customize > Custom > Edit GLOBAL CSS
.x-text p:empty,
.x-text br {
display: none;
}
.x-text .x-recent-posts {
margin-bottom: 10px;
}
The main and sidebar areas has no top margin at all. You can clear see it in the screenshots: http://prntscr.com/fz4z8u, http://prntscr.com/fz4zh5
In your homepage, the big white space is coming from the top padding of the very first section which you can see it here: http://prntscr.com/fz4zqk
Hope this helps.