Twenty Eleven Header(Slider) shows too much gap

hi, it was good before i added few more images for the slide i don’t know if ive done something wrong.. here is the site: https://www.umm.unioncollege.edu.ph/ and when you check the site using a mobile you’ll see the difference of position of my said problem. btw, im no good at php/css/html please bear with me. thanks in advance.