{{ $extra_header_class := "" }}
{{ with .Site.Params.sticky_header }}
  {{ $extra_header_class = "sticky" }}
{{ end }}
<header class="header {{ $extra_header_class }}">
    <div class="container wrap">

        {{ with .Site.Params.logo_on_white }}
        <a class="logo-link" href="{{ "/" | absLangURL }}">
            <img class="logo" width="150" height="40" src="{{ . | absURL }}" alt="{{ $.Site.Title | safeHTMLAttr }}">
        </a>
        {{ else }}
        <a class="site-title-link" href="{{ "/" | abs