If your trying to remove the dashed lines above the header and around the search bar and below the header right above the picture. Then I think this is what your looking for.
select the ‘Appearance’ dropdown
select the ‘Atahualpa Theme Options’
In ‘Header Area’ select ‘Style & edit HEADER AREA’
scroll down to ‘Search Box’
change color in this line: border: 1px dashed #cccccc;
do the same for ‘Horizontal Bar 1: Styling’,
and ‘Horizontal Bar 2: Styling’
For the verticle lines between your sidebars and center section
In ‘Sidebars & Widgets’ select ‘Style & configure SIDEBARS’
scroll down to ‘LEFT sidebar style’
change color in this line: border: 1px dashed #cccccc;
do the same for LEFT INNER sidebar style, RIGHT sidebar style, and RIGHT INNER INNER sidebar style
Hope this helps.