WhiteSur-gtk-theme/src/sass/gnome-shell/_drawing.scss

// generic drawing of more complex things

// provide font size in pt, with px fallback
@function pt($size: $root-font-size) {
  @return ($size * 0.75 / 1px) + pt;
}

// provide icon size in em, with px fallback
@function em($size: 16px) {
  @return ($size / $root-font-size) + em;
}

// Function to convert px values to em
@function to_em($input, $base: 16px) {
  // multiplied and divided by 1000 to make up for round() shortcoming
  $em_value: ($input / $base) * 1.091 * 1000;
  @return round($em_value) / 1000 * 1em;
}

// provide font size in rem, with px fallback
@mixin fontsize($size: 24, $base: 16) {
  font-size: round($size) + pt;
  //font-size: ($size / $base) * 1rem;
}

// Typography
// based on:
// https://material.io/guidelines/style/typography.html#typography-styles

@mixin font($size) {
  @if $size == display-4 {
    // font-family: $large-font-family;
    font-size: 112px;
    font-weight: 300;
    // line-height: 1;
  }

  @if $size == display-3 {
    // font-family: $large-font-family;
    font-size: 56px;
    font-weight: 400;
    // line-height: 1;
  }

  @if $size == display-2 {
    // font-family: $large-font-family;
    font-size: 45px;
    font-weight: 400;
    // line-height: 48px;
  }

  @if $size == display-1 {
    // font-family: $large-font-family;
    font-size: 34px;
    font-weight: 400;
    // line-height: 40px;
  }

  @if $size == headline {
    font-size: pt(24px);
    font-weight: 400;
    // line-height: 32px;
  }

  @if $size == title {
    font-size: pt(20px);
    font-weight: 500;
    // line-height: 1;
  }

  @if $size == subheading {
    font-size: pt($subheading-size);
    font-weight: 400;
    // line-height: 24px;
  }

  @if $size == body-2 {
    font-size: pt($root-font-size);
    font-weight: 500;
    // line-height: 24px;
  }

  @if $size == body-1 {
    font-size: pt($root-font-size);
    font-weight: 400;
    // line-height: 20px;
  }

  @if $size == caption {
    font-size: pt(12px);
    font-weight: 400;
    // line-height: 1;
  }

  @if $size == button {
    font-size: pt($root-font-size);
    font-weight: 500;
    // line-height: 20px;
  }
}


@mixin entry($t, $fc: $primary_color, $tc: $fg_color, $bc: $entry_shell_bg) {
//
// entry
//
// $t: entry type
// $fc: focus color
//

  @if $t == normal {
    background-color: $bc;
    border-radius: $circular_radius;
    border: 2px solid transparent !important;
    box-shadow: inset 0 0 0 1px rgba($borders_color, 0) !important;
    outline: none;
  }

  @if $t == hover {
    box-shadow: inset 0 0 0 1px rgba($borders_color, 0.1) !important;
    border: 2px solid transparent !important;
  }

  @if $t == focus {
    border: 2px solid lighten($fc, 15%) !important;
    box-shadow: inset 0 0 0 1px rgba($borders_color, 0) !important;
  }

  @if $t == insensitive {
    background-color: rgba($bc, 0.05);
    color: $disabled_fg_color;
  }

  @if $t == flat-normal {
    background-color: $bc;
    border-radius: $circular_radius;
    border: none !important;
    box-shadow: none !important;
    color: $tc;
  }

  @if $t == flat-hover {
    background-color: $bc;
    box-shadow: inset 0 0 0 1px rgba($borders_color, 0.05) !important;
    color: $tc;
  }

  @if $t == flat-focus {
    border: none !important;
    background-color: rgba($bc, 0.2);
    color: $tc;
  }

  @if $t == flat-insensitive {
    border: none !important;
    background-color: rgba($bc, 0.05);
    color: rgba($tc, 0.45);
  }
}

@mixin search_entry($t, $fc: $primary_color) {
//
// search_entry
//
// $t: search_entry type
// $fc: focus color
//

  @if $t == normal {
    background-color: rgba(white, 0.12);
    border-radius: $bd_radius;
    border-color: transparent !important;
    box-shadow: none !important;
  }

  @if $t == focus {
    border-color: transparent !important;
    background-color: rgba(white, 0.18);
    box-shadow: none !important;
  }

  @if $t == hover {
    background-color: rgba(white, 0.2);
    border-color: transparent !important;
    box-shadow: none !important;
  }

  @if $t == insensitive {
    color: $disabled_fg_color;
    border-color: transparent !important;
    box-shadow: none !important;
  }
}

@mixin button($t, $c: $button_bg, $tc: $fg_color) {
//
// button
//
// $t: button type
// $c: base color
// $tc: text color
//

  @if $t == normal {
    color: $tc;
    background-color: $c;
    border: 1px solid $button_borders;

    @if $variant=='light' { box-shadow: 0 1px 2px 0 rgba(black, 0.02); }
    @if $variant=='dark' {
      box-shadow: inset 0 1px $button_highlight;
    }

    text-shadow: none;
    icon-shadow: none;
  }

  @if $t == focus {
    color: $tc;
    text-shadow: none;
    icon-shadow: none;
    box-shadow: none !important;
  }

  @if $t == hover {
    color: $tc;
    border: 1px solid $button_borders;
    background-color: if($variant=='light', darken($c, 3%), lighten($c, 3%));
    text-shadow: none;
    icon-shadow: none;
  }

  @if $t == active {
    color: $tc;
    background-color: if($variant=='light', darken($c, 5%), lighten($c, 5%));
    border: 1px solid $button_borders;
    text-shadow: none;
    icon-shadow: none;
  }

  @if $t == checked {
    color: $tc;
    background-color: $selected_bg_color;
    border: 1px solid $selected_bg_color;
    text-shadow: none;
    icon-shadow: none;
  }

  @if $t == insensitive {
    color: if($tc == $fg_color, $disabled_fg_color, $tc);
    background-color: if($c == $base_color, $divider_color, $c);
    border-color: if($variant == 'light', $button_border, $dark_borders_color);
    text-shadow: none;
    icon-shadow: none;
  }

  @if $t == flat-normal {
    color: $tc;
    background-color: transparent;
    border-color: transparent;
    box-shadow: none;
    text-shadow: none;
    icon-shadow: none;
  }

  @if $t == flat-focus {
    color: $tc;
    text-shadow: none;
    icon-shadow: none;

    &, &:hover, &:active {
      box-shadow: none !important;
    }
  }

  @if $t == flat-hover {
    color: $tc;
    background-color: $divider_color;
    border-color: transparent;
    box-shadow: none;
    text-shadow: none;
    icon-shadow: none;
  }

  @if $t == flat-active {
    color: $tc;
    background-color: $track_color;
    border-color: transparent;
    box-shadow: none;
    text-shadow: none;
    icon-shadow: none;
  }

  @if $t == flat-checked {
    color: $tc;
    background-color: $divider_color;
    border-color: transparent;
    box-shadow: none;
    text-shadow: none;
    icon-shadow: none;
  }

  @if $t == flat-insensitive {
    color: if($tc == $fg_color, $disabled_fg_color, $tc);
    background-color: transparent;
    border-color: transparent;
    box-shadow: none;
    text-shadow: none;
    icon-shadow: none;
  }
}