Header
The ThemeKit RWD-X Header creates an h1 through h3 heading with a three color gradient, image or GIF text background. The background is achieved by setting the text-fill-color property to transparent and inserting the color gradient, image or animated GIF in the background.
The letters are embellished with a text stroke which has controls for width and color.
Font Size
Responsive text size is best achieved by using viewport units instead of pixels. Unfortunately EverWeb doesn't support these units at the time of writing.
The widget has controls for setting the font size for each device type.
Font Properties
Bold and italic are not desirable in web design. They make the design look outdated and, more importantly, causeproblems for those who have reading difficulties.
Letter Spacing
Letter spacing is another property which should be avoided unless it is absolutely necessary.
A feature heading like the one above is the exception since it usually employs a Google hosted display style font. Being of this century, these fonts generally don't have weight and style versions anyway.
The only good reason to add letter spacing is when adding properties such as text stroke and text shadow to a feature heading.