@vaadin/vaadin-material-styles/mixins/helper.js

Vaadin Material is a complete theme for Vaadin components, inspired by Google’s Material Design guidelines.

/**
 * @license
 * Copyright (c) 2017 - 2025 Vaadin Ltd.
 * This program is available under Apache License Version 2.0, available at https://vaadin.com/license/
 */
import '../color.js';
import { css } from '@vaadin/vaadin-themable-mixin/vaadin-themable-mixin.js';

export const helper = css`
  [part='helper-text'] {
    font-size: 0.75rem;
    line-height: 1;
    color: var(--material-secondary-text-color);
  }

  :host([has-helper]) [part='helper-text']::before {
    content: '';
    display: block;
    height: 6px;
  }

  /* According to Material guidelines, helper text should be hidden when error message is set and input is invalid */
  :host([has-helper][invalid][has-error-message]) [part='helper-text'] {
    display: none;
  }
`;