How to adjust text blocks CSS desktop and mobile & CSS command that decrease transparency when hover?

Site URL: https://salmon-prism-9ga5.squarespace.com/

Hi, I have a problem with my website project. I have 4 floating textblocks and i would like to adjust them in CSS, but I dont know how. I have tried google this, but I have not found a solution. In mobile view, the blocks are stuck together and I would like to have space between them.

Secound question: Is it possible increase visibility when hover? Now there is command that reduce opacity in logos in CSS. Is there some trick that when I move my cursor on logo it's transparency reduce ?

https://salmon-prism-9ga5.squarespace.com/
Password to website: woerks123

#1. Add to Design > Custom CSS

/* 4 boxes space on mobile */
@media screen and (max-width:767px) {
div#page-section-6255b74bc18dab1b063bba70 .html-block {
    margin-bottom: 50px;
}}

#2. Use this CSS

figure.gallery-reel-item:hover img {
    opacity: 1;
}

Thanks so much Tuanphan! You are my hero! 🔥