Yes! Responsive CSS layouts are supported in HTML5 and CSS exports.

Requirements:

• CSS Screen Tag (default): ${css|screen:default}
• CSS Screen Tag: ${css|screen:#target_size#}
• At least 2 layouts (folders) with CSS Screen Tags

Example folder structure:

Exporting:

To enable Responsive CSS layouts, you must enable [Customize] and [Responsive CSS] in exports view:

Optional:

You can also include responsive image assets to reduce the bandwidth on smaller devices such as mobiles:

Resources:

• View the Responsive webpage sample
• Download the Responsive PSD template