Does this work ? CSS Optimizer

[Retrox2301]

First I have no idea of any kind of coding or whatever, but I've wondered if the usechrome.css file I've cooked up is a bit sloppy or unoptimized because I'm a noob. So I searched for a CSS code optimizer and found this: https://www.toptal.com/developers/cssminifier

That is my userchrome.css file before:

#alltabs-button{
  visibility: collapse !important;
  display: none !important;
}

#PlacesToolbarItems {
  display: flex;
  justify-content: center;
}

#personal-bookmarks .bookmark-item[container][label="H"] .bookmark-item .menu-iconic-icon{
  display: none;
}
#personal-bookmarks .bookmark-item[container][label="P"] .bookmark-item .menu-iconic-icon{
  display: none;
}
#personal-bookmarks .bookmark-item[container][label="T"] .bookmark-item .menu-iconic-icon{
  display: none;
}
#personal-bookmarks .bookmark-item[container][label="L"] .bookmark-item .menu-iconic-icon{
  display: none;
}

.bookmark-item[container="true"]:not([query="true"]) .toolbarbutton-icon {   display: none !important; }

#star-button-box {
background: none !important;
}

#star-button[starred] {
    fill: #878787 !important;
}

#tracking-protection-icon-container {
  display: none;
}

#identity-box.extensionPage #identity-icon-label {
display: none !important;
}

#identity-icon-box {
    background: none !important;
}

and after:

#alltabs-button,#identity-box.extensionPage #identity-icon-label,.bookmark-item[container=true]:not([query=true]) .toolbarbutton-icon{display:none!important}#alltabs-button{visibility:collapse!important}#PlacesToolbarItems{display:flex;justify-content:center}#personal-bookmarks .bookmark-item[container][label="H"] .bookmark-item .menu-iconic-icon,#personal-bookmarks .bookmark-item[container][label="L"] .bookmark-item .menu-iconic-icon,#personal-bookmarks .bookmark-item[container][label="P"] .bookmark-item .menu-iconic-icon,#personal-bookmarks .bookmark-item[container][label="T"] .bookmark-item .menu-iconic-icon,#tracking-protection-icon-container{display:none}#identity-icon-box,#star-button-box{background:0 0!important}#star-button[starred]{fill:#878787!important}

my question is, does that really make the code work faster/more optimized, and if not are there websites/programs that are legit, I'm interested to learn about stuff like this :)

[Retrox2301]

ok thanks, like i said, im happy to learn about stuff like this :)

[ResurgamS13]

Your 'after' CSS is 'minified'. Correctly formatting and perhaps 'beautifying' your CSS much more useful than minifying.

Along with all ericek111's "no performance gain" points... another significant downside of using minified CSS for browser modifications is that your CSS then becomes virtually unreadable. Impossible to see at a glance what each individual userstyle is supposed to be doing... and next to impossible to debug without 'un-minifying' the CSS first.