Hi roemer,

I had the same issue and it was driving me mad! If you are logged into your website (signed into the WordPress dashboard), there will be a gap at the top when you are viewing/previewing the website. This is due to the default admin toolbar setting.

Option One: (Temporary Solution)

• Log out of WordPress and refresh your page -OR- open up your website in an incognito window.
• The gap should now be gone.

Option Two: (Permanent Solution)

• Open up your WP dashboard
• Go to Users >> Your Profile
• Under Personal Options, uncheck the ‘Toolbar’ box. You DO NOT want to ‘Show Toolbar when viewing site.’
• Now go back to your live website or preview page and refresh the page. The gap should now be gone.

For more detailed instructions (with images), visit this link: http://www.cryoutcreations.eu/wordpress-themes/wordpress-tutorials/how-to-hide-the-wordpress-admin-bar.

I hope this helps!