Mosaic Tiles can be organized on a grid up to 4 columns wide. Each tile can be full width or in halves, thirds, or quarters of a row.
While in Edit mode, press the Alt key on your keyboard to enter Advanced mode. It will allow you to see the boundaries of the rows and tiles, labels for the tiles, and CSS classes for the rows. To exit Advanced mode, press Alt again.
Also in the advanced mode, you’re able to add custom classes on rows.
To nest columns inside a cell, drag a tile, hold the Ctrl key and then drop the tile close to an existing one (either above or below it) in accordance to the shown insert marker. This creates a new row within the cell. In Advanced mode, the row has the class "mosaic-innergrid-row".
Drag and drop tiles in the new row to create adjacent subcolumns.
The resulting page.
Fluid row styles work best on pages without portlets.
To create fluid (full width) rows in the layout, select any tile in the row and choose Fluid from the Format menu.
This will add the CSS class "mosaic-grid-row-fluid" to the row.