To build a two-column (50/50%) layout, start with a container with a class of ui-grid-a, and add two child containers inside it classed with ui-block-a for the first column and ui-block-b for the second. On the blocks below, we're adding two classes: ui-bar to add the default bar padding and ui-bar-a to apply the background and font styling for the "a" toolbar theme swatch. For illustration purposes, an inline style="height:60px" attribute is also added to each grid to set each to a standard height.