Left Align Oracle Apex (Sub-)regions

How to left align Oracle sub-regions

Create more than one sub-regions, for example 3 of them, namely query1, query2 and query3. Modify grid layout and region attributes for each of sub-regions.

Query 1:
Start New Grid: NO
Start new Row: NO
Column: 1
Column Span: Automatic
Column Attributes: style="width:420px;"
Region Attributes: style="width:400px;height:150px;background-color:#DEE9E8;"

Query 2:
Start New Grid: NO
Start new Row: NO
Column: 2
Column Span: Automatic
Column Attributes: style="width:420px;"
Region Attributes: style="width:400px;height:150px;background-color:#F9FDD9;"
Query 3:
Start New Grid: NO
Start new Row: NO
Column: 3
Column Span: Automatic
Column Attributes: (left blank)
Region Attributes: style="width:400px;height:150px;background-color:#CEF6CE;"

In this example column width (420px) is larger than the region width (400px), therefore there are spaces between two regions. Column attributes for the last sub-region is left blank, to make the 100% table width.