Syntax Error On Line 1

Hello, my ultimate goal is to get a small icon, in line with the text. It has not worked yet, and am seeing a "Syntax Error On Line 1" message though I can't figure out what the error is. Any ideas?

Here is the code:

{
  transform:translateY(100%);
  width:100% !important;
  text-align:center;
  border-bottom: 1px solid #999;
  overflow: auto;
  overflow-x:auto;
  white-space: nowrap;
  z-index:99;
}
.tab-btn{
  max-width:150px;
  display: inline-block;
  border-radius:3px 3px 0 0;
  border:1px solid #999;
  padding: 12px 18px;
  font-size:1.2em;
  background:white;
  margin-bottom:none !important;
  border:none !important;
  &:not(:first-of-type){
  margin-left:10px;
  }
}
.tab-btn.active{
  background:lightblue;
}

section.tab-section-hide{
  display:none !important;
}
section.tab-section-show{
  display:flex !important;
}

.image1{
color: transparent;
background-image:url(first-image-url-herehttps://static1.squarespace.com/static/55ca08f9e4b0d196f15712be/t/646b7e6f96cd295d948807d4/1684766319855/Leaving+Website.png);
 background-size:cover;
 background-repeat:no-repeat
 }

You have no selector for your first rule-set. A ruleset can not start with {.

Thank you! Do you know if there's a way to look at my css history in squarespace to see what got deleted there? 

SS provides no history, backups, or revision control.

It might be possible to retrieve that info from one of the search engine caches or archive.org's wayback machine.

You'd have to read up on the web to learn how to do that.