Table elements, such as HTML elements, are automatically formatted relative to a change in visual appearance of a displayed decorative panel. The decorative panel comprises a plurality of separate but visually related regions defined by the table elements, and organized in predefined logical relationships to each other. A visual change causes an automatic revision to one or more attributes of the table elements that define the regions affected by the visual change. The visual change and automatic formatting are preferably accomplished with a Web page design tool, which identifies the decorative panel from comments associated with the table elements but do not affect rendering by a conventional browser. Visual properties of the decorative panel are mapped to the attributes, so that when the visual appearance is changed, a corresponding attribute is automatically revised. The resulting revised table elements are validated against predetermined inference rules that define valid patterns of regions.