Resizing Banner Images in CSS for Mobile

Site URL: http://www.get-ripe.com

Hi Friends, 

Thanks in advance for any support. I'm struggling trying to resize the banner sizes for my website www.get-ripe.com in CSS. Any help would be greatly appreciated. I'm looking to resize the banner on all pages except for the Digital Sessions & Blog page. Again, I appreciate you! 

Have a great weekend! 
Megan

Add to Page Settings > Advanced > Header

<style>
  @media screen and (max-width:767px) {
  #page section:first-child {
    min-height: 20vh !important;
    height: 40vh !important;
}
  }
</style>