if(get("#316")) {#316;loadlayout("normal");}else {#316; if(get("#1061")){#1061;}}
EDIT: Perhaps a better way to cycle between Light and Dark mode (without the menu bar in Dark) especially if you don't use or want to use layouts would be this:
if(get("#316")){if(!get("#1061")){#1061;}#316;}else{#316; if(get("#1061")){#1061;}}
You can also have the right click of the same CTB bring up the Main Menu as a pop-up with:
if(!get('#1061')){popupmainmenu;}