How to replicate this header?

Rest is all perfect, thanks for your amazing support. Please help me in resolving above issue.

Yes, with screenshot it's easier to understand your issue, please do so next time.

So the issue is a CSS conflict coming from the 3rd part search, try add this:

.dgwt-wcas-search-wrapp {
    width: auto;
}

GPians are amazing. Thank you very much. It is resolved now.