如何让导航栏下拉菜单与身体重叠？

Question

我试图让导航栏上的下拉菜单与身体重叠。我试过z-index：1;但下拉菜单仍由身体覆盖，如何让下拉菜单与身体重叠？

此外，当我尝试在移动模式下使用导航栏时菜单未与导航栏对齐，如何使其与导航栏对齐？

谢谢你的帮助！

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