material-components_material-web/packages/linear-progress/_linear-progress.scss

/**
 * @license
 * Copyright 2020 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */
@use '@material/theme/custom-properties';
@use '@material/linear-progress' as linearprogress;
@use '@material/theme/theme';

@mixin core-styles() {
  @include linearprogress.core-styles();

  :host {
    display: block;
  }

  .mdc-linear-progress__buffer-bar {
    @include theme.property(
      background-color,
      custom-properties.create(
        --mdc-linear-progress-buffer-color,
        linearprogress.$baseline-buffer-color
      )
    );
  }
  .mdc-linear-progress__buffer-dots {
    @include theme.property(
      background-image,
      custom-properties.create(
        --mdc-linear-progress-buffering-dots-image,
        url("data:image/svg+xml,%3Csvg version='1.1' xmlns='http://www.w3.org/2000/svg' xmlns:xlink='http://www.w3.org/1999/xlink' x='0px' y='0px' enable-background='new 0 0 5 2' xml:space='preserve' viewBox='0 0 5 2' preserveAspectRatio='none slice'%3E%3Ccircle cx='1' cy='1' r='1' fill='%23e6e6e6'/%3E%3C/svg%3E")
      )
    );
  }
}