core/misc/dialog/off-canvas/css/messages.pcss.css
/**
 * @file
 * Styling for messages in the off-canvas dialog.
 *
 * @internal
 */

#drupal-off-canvas-wrapper {
  --off-canvas-messages-icon-size: 20px;
  --off-canvas-messages-background-color: #f3faef;
  --off-canvas-messages-text-color-status: #325e1c;
  --off-canvas-messages-text-color-warning: #734c00;
  --off-canvas-messages-text-color-error: #a51b00;
  --off-canvas-messages-icon-status: url(../../../icons/73b355/check.svg);
  --off-canvas-messages-icon-warning: url(../../../icons/e29700/warning.svg);
  --off-canvas-messages-icon-error: url(../../../icons/e32700/error.svg);

  & .messages {
    position: relative; /* Anchor ::before pseudo-element. */
    margin-top: calc(2 * var(--off-canvas-vertical-spacing-unit));
    padding: calc(2 * var(--off-canvas-vertical-spacing-unit));
    padding-inline-start: calc(2 * var(--off-canvas-messages-icon-size)); /* Room for icon. */
    border: solid 1px transparent;
    background-color: var(--off-canvas-messages-background-color);

    /* Icon. */
    &::before {
      position: absolute;
      top: 50%;
      display: block;
      width: var(--off-canvas-messages-icon-size);
      height: var(--off-canvas-messages-icon-size);
      content: "";
      transform: translateY(-50%);
      background-repeat: no-repeat;
      background-size: contain;
      inset-inline-start: 10px;

      @media (forced-colors: active) {
        background: canvastext;
        mask-repeat: no-repeat;
        mask-size: contain;
      }
    }
  }

  & h2 {
    margin-top: 0;
  }

  /*
   * Some themes (Olivero) insert SVG icon. We use a background icon, so we
   * need to remove this.
   */
  & .messages__icon,
  & .messages__close {
    display: none;
  }

  & .messages__list {
    margin: 0;
    padding-inline-start: 20px;
  }

  & .messages abbr {
    text-decoration: none;
  }

  & .messages--status {
    color: var(--off-canvas-messages-text-color-status);

    &::before {
      background-image: var(--off-canvas-messages-icon-status);

      @media (forced-colors: active) {
        background: canvastext;
        mask-image: var(--off-canvas-messages-icon-status);
      }
    }
  }

  & .messages--warning {
    color: var(--off-canvas-messages-text-color-warning);

    &::before {
      background-image: var(--off-canvas-messages-icon-warning);

      @media (forced-colors: active) {
        background: canvastext;
        mask-image: var(--off-canvas-messages-icon-warning);
      }
    }
  }

  & .messages--error {
    color: var(--off-canvas-messages-text-color-error);

    &::before {
      background-image: var(--off-canvas-messages-icon-error);

      @media (forced-colors: active) {
        background: canvastext;
        mask-image: var(--off-canvas-messages-icon-error);
      }
    }
  }
}
