Resizing hero image on Foster template for mobile

Hi guys, I am using a hero image on my homepage that works well on desktop. I've tried to resize it for mobile use which I've managed but there are two issues I'm trying to tackle with the mobile display:

1) there is a big space between the hero image and text that I want to remove

2) I was hoping I could get the hero image to scroll on the mobile phone, as it does on desktop: https://www.bethedwardsnutrition.com/

Any help gratefully received thank you!

Use this new CSS code

@media screen and (max-width: 640px) {
    body.homepage .Parallax-item:first-child img {
        width:100% !important;
        height: auto !important;
        left: 0 !important;
        top: 0 !important;
    }
    section#hero-image-foster {
        height: 200px;
    }
    section#hero-image-foster .spacer-block, section#introduction .spacer-block {
        display: none;
    }
}