Logo / site-title centred over the full width in one line

I want to do Logo (left) | site-title / site- description (centred over the full width of header) | all in one line Header: -------------------------- 100 % ------------------------------- logo (25 % - left) | site-titel (75 % - center) site-description (75% - center) -------------------------- 100 % ------------------------------- I have tried #site-logo, #hgroup { display: inline; float: right; } and #site-title {text-align: center;} #site-description {text-align: center;} OK, - logo on the left side - all in one line with site-titel and site-description but site-titel and site-description are not centred over the full width of the header Header: -------------------------- 100 % ------------------------------- logo | site-titel (center) site-description (center) -------------------------- 100 % ------------------------------- What can I do?