CSS:固定位置，正确:0px但不符合max-width

I cannot get positioning, max-width, and 'right: 0px' to work together in harmony! I'm creating a div that is fixed on my site in the upper right corner. The content of the page has a max-width of 1000px, however the label only obeys my rule of 'right: 0px' and sticks to the right, disobeying once max-width has been reached. It should also be noted that by default, the div is in the upper left and obeys the max-width (if I type 'left: 0px;' though, it does not obey the rule and it sticks to the left). I cannot get positioning, max-width, and 'right