My blog is total 10 post's, 5 post's with 'job' label and 5 "admit card" label I set condition for 'job' label

<b:if cond='data:blog.post.label == "job"'><!-- for label 'job' --><style>.body {width:1200px;}</style></b:if>

That is, whenever there is a post index of the job label, then the style (body width) the change