Prevent Right-Aligned Nav Sub-Menu w/ Right Dropdown Direction From Overflowing Viewport

/* Prevent sub-menu dropdown of the final item in right-aligned navigation from overflowing the viewport */
.dropdown-hover .main-navigation:not(.toggled) ul li:last-child:hover>ul {
   right: 0;
}
.dropdown-hover .main-navigation:not(.toggled) ul li:last-child ul li:hover>ul {
   left: -100%;
}

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