How can I customize the PrizmDoc Viewer UI to change the positioning of the menu bars?

For this use case, you will want to leave the "pcc-nav-tabset" alone (since it's already at the top), and make modifications to the other elements:

1. Open "viewer.css"
   
   
2. Search for "pcc-tab-pane"
   
   
3. Make the following changes:
   
   

   .pccv .pcc-tab-pane {
   visibility: hidden;
   position: absolute;
   height: 40px;
   top: 29px; // change to "top: 69px". This will leave enough room for the other menu bar, which has a height of 40px.
   left: 0;
   right: 0;
   line-height: 37px;
   padding: 0 10px;
   background: #f2f3f6;
   z-index: 4;
   -webkit-box-shadow: 0 0 4px 1px rgba(0, 0, 0, 0.4);
   box-shadow: 0 0 4px 1px rgba(0, 0, 0, 0.4);
   }

   
   
4. Search for "pcc-tools-tabset"
   
   
5. Make the following changes:

   .pccv .pcc-tools-tabset {
   position: absolute;
   width: 100%;
   height: 40px;
   background: #383a3f;
   bottom: 0; // change to "top: 29px". this will move the position to the top, right under the original top menu bar,
   // which has a height of 29px.
   text-align: center;
   z-index: 3;
   will-change: opacity;
   }

   
   
   

   
   
6. Search for "data-pcc-pagelist"
   
   
7. Make the following changes:
   
   

   .pccv [data-pcc-pagelist] {
       position: relative;
       width: 100%;
       height: 100%;
       padding-top: 69px; // change to 109 (add the heights of the menu bars together, 40px + 40px +29px)
       padding-bottom: 40px; // change to 0px, since we moved the bottom menu bar
   }