Debut theme fixed header and spaces in bottom on mobile view

Store Design
1

Dear friends,

I’m trying for few days to solve some problems, but it seems, that new changes on theme.css breaks old ones.

I had passed all this this codes:

#SearchDrawer {
  z-index:1001;
}

#shopify-section-header {
    position: sticky;
    top: 0;
    z-index: 1001;
    -webkit-box-shadow:0px 2px 4px 0px rgba(0,0,0,.1);
    -moz-box-shadow:0px 2px 4px 0px rgba(0,0,0,.1);
    -ms-box-shadow:0px 2px 4px 0px rgba(0,0,0,.1);
    -o-box-shadow:0px 2px 4px 0px rgba(0,0,0,.1);
    box-shadow:0px 2px 4px 0px rgba(0,0,0,.1);
}

.page-container {
  padding-top: 0 !important;
  width:100%;
position: absolute;
}

.site-footer__copyright-content a:hover, .site-footer__linklist-item a:hover, .site-footer__rte a:hover, .site-nav__link--button:focus, .site-nav__link--button:hover ;, .site-nav__link:focus .site-nav__label, .site-nav__link:not([disabled]):hover { color: #eb4d86 !important; } .site-nav__label{
border-bottom: 0px !important;
}
a.site-nav__link.site-nav__link--main.site-nav__link--active {
    color: #eb4d86;
}
.site-footer__social-icons .social-icons__link:hover {
    color: #eb4d86 !important; 
  
ul.site-footer__linklist.list--inline li a:hover{
    bortder-bottom:none! important;
}

I wanted to have

a) a sticky header for computer view and mobile view (worked for computer only but now it’s not working anymore)

b) change the header hover color to this color #eb4d86 (worked and is still working)

c) delete the hover underline on the footer menu (never worked)

d) delete a space that was on computer view under the footer menu (is working for computer view but on mobile i have two spaces that i would like to kill - screenshot)

Untitled design (14).png
Untitled design (14).png500×500 44.6 KB

Can someone help me to fix all of that?

The website is: roombles.live

Thank you!