Hello,

To reduce the height of the header image, please add the below given CSS by going to Admin Panel > Appearance > Customize > Additional CSS

#featured-slider-section .featured-slider .slick-track  article {
    height: 75vh;
}

Hope this helps.

For any further query/confusion, feel free to write back to us.

Best Regards!!

Hello,

Do you want to decrease the height in the posts as well?

Also, please post your site URL so that we can provide the precise fix.

Thank you.

Hello,

Please add below given to reduce the height all over the site.

#page-site-header {
    height: 50vh;
}

Hope this helps.

Thank you.