style.scss

// https://gitlab.gnome.org/GNOME/gtk/-/blob/gtk-3-24/gtk/theme/Adwaita/_colors-public.scss
$theme_fg_color: "@theme_fg_color";
$theme_bg_color: "@theme_bg_color";

* {
  background: transparent;
  border: none;
  border-radius: 0;
  color: #{$theme_fg_color};
  font-family: "JetBrainsMono Nerd Font";
  font-weight: 400;
  font-size: 0.9rem;
}

window.Bar {
  > centerbox {
    background: #{$theme_bg_color};
    border: 1px solid #{$theme_fg_color};
    border-radius: 0;
    margin: 12px 12px 0px 12px;
    padding: 6px;
  }

  button {
    background: #{$theme_bg_color};
    border: lightgrey;
    border-radius: 0;
    margin: 2px;
  }
  button:hover {
    background: lightgrey;
  }
}

window.AppMenu,
window.SystemMenu {
  > box {
    background: #{$theme_bg_color};
    border: 1px solid #{$theme_fg_color};
    border-radius: 0;
    margin: 12px;
  }

  > box.menuouter {
    padding: 6px;
  }

  box.power,
  box.audio {
    margin-bottom: 6px;
  }

  box.system > button.network,
  box.system > button.tailscale {
    margin-bottom: 6px;
  }

  button {
    background: #{$theme_bg_color};
    border: 1px solid lightgrey;
    border-radius: 0;
    margin: 2px;
  }

  button.on {
    background: lightgrey;
  }

  button:hover {
    background: lightgrey;
  }

  slider {
    background: #{$theme_bg_color};
  }

  trough {
    background: #{$theme_fg_color};
  }
}