Viewport Height Image
It should be obvious that an item like a full size background image cannot be inserted into a responsive page design. The image would be far too large to download to a mobile phone over a wireless cellular network.
Viewport Height
An item can be made to fill the browser or device window by giving it 100% width and setting its height to 100vh.
Viewport Height (vh) — This unit is based on the height of the viewport. A value of 1vh is equal to 1% of the viewport height.
If the item is fixed in position, the content below it will scroll over it and the effect will be the same as a background item without the huge penalty of downloading images in excess of 1Mb.
Images
The image is inserted in three different sizes - one for computers, one for narrow browser widths and tablets in landscape mode and one for tablets in portrait mode which will give retina @2x quality when viewed on phones in portrait mode.
The large image used in this demo is 1600px wide with a file size of 360Kb.
The medium image is 1200px wide and weigh in at under 200Kb.
The smaller image is 800px wide with a file size of only 40Kb.
These images are inserted using the HTML5 <picture> element which means that they can also have alt text for the search engines.
Overlay
The full size overlay can animate in on page load and has controls for the animation time and delay which are set in seconds.
The overlay can show a centered heading and paragraph with an option for a CTA style link. The items can be spaced out vertically and the link can be configured to open internal or external pages and in a new window if required.
This group has a maximum width setting and can also show a background with controls for the color and its opacity. When this background is set, the overlay opacity can be reduced to zero if required.
NOTE:
At the time of writing, EverWeb cannot display items which are 100vh on the design canvas. The item will be displayed at 600px in height but will obviously fill the viewport when previewed in the browser.
When creating responsive pages, it is really important to test the layout in the browser and in an iPad and iPhone in the iOS Simulator.