chrome/browser/resources/bluetooth_internals/snackbar.html

<style>
  :host {
    background-color: #323232;
    border-radius: 2px;
    bottom: 0;
    color: #f1f1f1;
    display: flex;
    font-size: 1.5em;
    justify-content: center;
    left: 0;
    margin: 0 auto;
    max-height: 52px;
    min-height: 20px;
    opacity: 0;
    padding: 14px 24px;
    position: fixed;
    right: 0;
    transform: translate3d(0, 80px, 0);
    transition: opacity var(--fade-duration), transform var(--fade-duration),
        visibility var(--fade-duration);
    transition-timing-function: var(--md-timing-function);
    visibility: hidden;
  }

  a {
    display: flex;
    flex-direction: column;
    justify-content: center;
    margin-inline-start: auto;
    text-transform: uppercase;
  }

  @media screen and (min-width: 601px) {
    :host {
      max-width: 568px;
      min-width: 288px;
    }
  }

  @media screen and (max-width: 600px) {
    :host {
      border-radius: 0;
      margin: 0;
      right: 0;
    }
  }

  div {
    align-self: flex-start;
    margin-inline-end: 24px;
  }

  a {
    color: rgb(238, 255, 65);
  }

  :host(.success) {
    background-color: rgb(76, 175, 80);
  }

  :host(.warning) {
    background-color: rgb(255, 152, 0);
  }

  :host(.warning) a {
    color: rgb(17, 85, 204);
  }

  :host(.error) {
    background-color: rgb(244, 67, 54);
  }

  :host(.open) {
    opacity: 1;
    transform: translate3d(0, 0, 0);
    visibility: visible;
  }
</style>
<div id="message"></div>
<a is="action-link"></a>