materio-d8/web/themes/custom/materiotheme/assets/styles/base/_layout.scss

body, html{
  position: relative;
  width: 100%;
  height:100%;
  font-family: sans-serif;
  font-style: normal;
  margin:0;
  padding:0;
}
body.toolbar-horizontal.toolbar-themes.toolbar-no-tabs{
  padding-top: 24px!important;
}


//  _  _             _
// | || |___ __ _ __| |___ _ _
// | __ / -_) _` / _` / -_) '_|
// |_||_\___\__,_\__,_\___|_|

header[role="banner"]{
  background-color: #fff;
  overflow: visible;
  position: fixed;
  z-index: 10;
  width:100vw;
  // outline: 1px solid blue;
  height: $header_height;
  .wrapper{
    .header-block{
      min-height: 15px;
      font-size: 0;
      &>*{
        display: inline-block;
        vertical-align: top;
        font-size: $base_font_size;
      }
    }
  }
}


//  __  __      _
// |  \/  |__ _(_)_ _
// | |\/| / _` | | ' \
// |_|  |_\__,_|_|_||_|

main[role="main"]{
  padding-top: $header_height;
}