The admin menus in LightCMS are added dynamically as inline elements that flow with the rest of the page's content, usually "pushing" other content down in order to make room. Often designers who choose to create layouts with an absolutely positioned structure will run into issues because the layout cannot adapt to the changing content. Furthermore, the drop-down menus in the admin view use a variant of the Suckerfish method which requires some positioning via CSS.
Because the menus are inline with the rest of the page, they are subject to any CSS rules that might be in effect on that page and potentially their appearance/behavior can be modified unintentionally. I would recommend that anyone looking to explore these issues becomes familiar with the /Styles/water.css that is added to every page and avoid overriding the CSS rules in that document. To view the water.css stylesheet you will need an add-on for Firefox such as the Web Developer toolbar. It is also helpful to avoid re-using the same class names.
Posted on Tue, June 8, 2010