Few things for posting on this forum.
When you ask for support, it would be best for you to provide as *much* information as possible to help us out. Posting just one sentence does not give us any information on anything, and would most likely diminish your chances of getting support, and it will delay solving your issue.
If you don’t say what theme your using, I am going to assume that it’s not a buddypress issue, and redirect you to the wordpress support forums: https://www.wordpress.org/support
if you are using default theme, look at the header and specify your preferences there.
`#header {
width: 960px;`
i am using buddypress default theme
Ok, so I would do the CSS rule I posted above.
But I wouldn’t really recommend putting a custom px for the width of the header, because you can make the header fit nicely on your current browser, and computer screen width, but as soon as you go to a new computer with different screen widths, the header will not stretch across the entire screen because you have specified it to be a specific width.
You don’t even need to specify the “width” in the theme, just make sure you have:
`position: relative;`