Sassy-Min-Progress.scss

$color-value: green;
$border-radius-value: 20px;
$box-shadow-value: inset 5px 5px 5px red;

@mixin progress{
  -webkit-appearance: none;
  border: none;
  width: 160px;
  height: 16px;
  overflow: hidden;
  
  &::-webkit-progress-bar{
    background: transparent;
  }
  &::-webkit-progress-value{
    @content;
  }
  &::-moz-progress-bar{
    @content;
  }
  &::-ms-fill{
    @content;
  }
}

@mixin range-track{
  &::-webkit-slider-runnable-track{
    -webkit-appearance: none;
    @content;
  }
  &::-moz-range-track{
    @content;
  }
  &::-ms-track, &::-ms-fill-lower {
    border: 0;
    @content;
  }
}

@mixin range-thumb{
  &::-webkit-slider-thumb{
    -webkit-appearance: none;
    @content;
  }
  &::-moz-range-thumb{
    border: 0;
    @content;
  }
  &::-ms-tooltip {
    display: none;
  }
  &::-ms-thumb {
    @content;
  }
}

progress{
  background: red;
  border-radius: 30px;
  @include progress{
    background: yellow;
    border-radius: 3px;
  };
}

Sassy-Progress-Bar.scss

$progress-width: 160px;
$progress-height: 16px;
$color-bar: lightsalmon;
$color-value: yellow;
$border-radius-bar: 20px;
$border-radius-value: 20px;
$box-shadow-bar: 3px 3px 5px red;
$box-shadow-value: inset 5px 5px 5px red;

@mixin progress{
  -webkit-appearance: none;
  border: none;
  width: $progress-width;
  height: $progress-height;
  overflow: hidden;
  background: $color-bar;
  border-radius: $border-radius-bar;
  box-shadow: $box-shadow-bar;
  
  &::-webkit-progress-bar{
    background: transparent;
  }
  &::-webkit-progress-value{
    background: $color-value;
    border-radius: $border-radius-value;
    box-shadow: $box-shadow-value;
  }
  &::-moz-color-bar{
    background: $color-value;
    border-radius: $border-radius-value;
    box-shadow: $box-shadow-value;
  }
  &::-ms-fill{
    background: $color-value;
    border-radius: $border-radius-value;
    box-shadow: $box-shadow-value;
  }
}

progress{
  @include progress;
}