Sure, you can add this:
#navigator-toolbox{
transition: margin-bottom 135ms ease-in var(--uc-autohide-toolbar-delay) !important;
}
#navigator-toolbox:is(:hover,:focus-within),
#mainPopupSet:has(> [panelopen]:not(#ask-chat-shortcuts,#selection-shortcut-action-panel,#chat-shortcuts-options-panel,#tab-preview-panel)) ~ #navigator-toolbox{
margin-bottom: 0 !important;
transition-delay: 100ms !important;
}
You could probably get things wayy simpler than what that style is doing if you want web-content to move, although it probably still won't be quite trivial. But adding the above after autohide_bookmarks_and_main_toolbars.css should work fine I guess.