Userstyle to return GitHub's light-themend header (in light mode)

GithubReturnLightThemedHeader.user.css

/* ==UserStyle==
@name         Github Return Light Themed Header
@namespace    https://phoenix616.dev
@preprocessor less
@version      0.1.0
@author       Phoenix616 aka Max Lee (https://phoenix616.dev)
@homepageURL  https://gist.github.com/Phoenix616/3be078a482e50f5e9cc4cd8e0d7272b7/
@updateURL    https://gist.github.com/Phoenix616/3be078a482e50f5e9cc4cd8e0d7272b7/raw/37c94748eaec6dec1d3f1bd10460d7159f4b1ea0/GithubReturnLightThemedHeader.user.css
==/UserStyle== */

@-moz-document domain("github.com") {
[data-color-mode=light] {
 .Header {
    background-color: #F5F5F5 !important;
  }

  .js-header-wrapper {
	border-bottom: 1px solid #E5E5E5 !important;
    background-color: #F5F5F5 !important;
  }

  .Header .octicon,
  .Header .dropdown-caret {
    color: #555 !important;
  }
  
  .Header .header-logo-invertocat,
  .Header .header-logo-wordmark {
    color: #555 !important;
  }
  
  .Header .header-logo-invertocat:hover,
  .Header .header-logo-wordmark:hover {
    color: #4078C0 !important;
  }
  
  .Header .Header-link,
  .Header .HeaderNavlink,
  .Header div.HeaderNavlink a,
  .Header .notification-indicator {
    color: #555 !important;
  }
  
  .Header .HeaderNavlink:hover,
  .Header .HeaderNavlink:focus,
  .Header .HeaderNavlink:hover,
  .Header .HeaderNavlink:focus,
  .Header div.HeaderNavlink a:hover,
  .Header div.HeaderNavlink a:focus,
  .Header .notification-indicator:hover,
  .Header .notification-indicator:focus {
    color: #4078c0 !important;
  }
  
  .Header .HeaderNavlink:hover .dropdown-caret,
  .Header .HeaderNavlink:focus .dropdown-caret,
  .Header .HeaderNavlink:hover .dropdown-caret,
  .Header .HeaderNavlink:focus .dropdown-caret {
    border-top-color: #4078c0 !important;
  }
  
  .Header .notification-indicator .mail-status {
    border-color: #f3f3f3 !important;
  }
  
  .Header .header-search {
    font-size: 14px !important;
  }
  
  .Header .form-control.header-search-wrapper {
    line-height: 21px !important;
  }
  
  .Header .header-search-scope {
    font-size: 12px !important;
    line-height: 20px !important;
    color: #767676 !important;
    border-right-color: #EEE !important;
  }
  
  .Header .header-search-scope:empty+.header-search-input {
    /*width: 100%; */ /* 99.999% */
  }
  
  .Header .header-search-wrapper {
    min-height: 0 !important;
    font-size: 14px !important;
    color: #333 !important;
    background-color: #FFF !important;
    border: 1px solid #DDD !important;
    box-shadow: inset 0 1px 2px rgba(0,0,0,0.075) !important;
  }
  
  .Header .header-search-wrapper.focus {
    background-color: #FFF !important;
    box-shadow: inset 0 1px 2px rgba(0,0,0,0.075), 0 0 5px rgba(81,167,232,0.5) !important;
    border-color: #51A7E8 !important;
  }
  
  .Header .header-search-wrapper.focus .header-search-scope {
    color: #4078C0 !important;
    background-color: #EDF2F9 !important;
    border-right-color: #C6D7EC !important;
  }
  
  .Header .header-search-input {
    min-height: 26px !important;
    font-size: 14px !important;
    color: #333 !important;
  }
  
  .Header .header-search-key-slash {
    filter: invert() brightness(3) !important;
  }
  
  .Header .header-search-input::-webkit-input-placeholder {
    color: #999 !important;/*AAA*/
  }
  .Header .header-search-input::-moz-placeholder {
    color: #999 !important;/*AAA*/
  }
  .Header .header-search-input:-ms-input-placeholder {
    color: #999 !important;/*AAA*/
  }
  .Header .header-search-input::placeholder {
    color: #999 !important;/*AAA*/
  }
}
}