@vaadin/vaadin-lumo-styles/src/components/form-item.css

Lumo is a design system foundation for modern web applications, used by Vaadin components

/**
 * @license
 * Copyright (c) 2017 - 2026 Vaadin Ltd.
 * This program is available under Apache License Version 2.0, available at https://vaadin.com/license/
 */
@media lumo_components_form-item {
  [part='label'] {
    /* font-weight, margin-bottom, transition and line-height same as for part label in text-field */
    color: var(--lumo-secondary-text-color);
    font-family: var(--lumo-font-family);
    font-size: var(--lumo-font-size-s);
    font-weight: 500;
    margin-top: var(--lumo-space-m);
    margin-left: calc(var(--lumo-border-radius-m) / 4);
    margin-bottom: var(--lumo-space-xs);
    line-height: 1.333;
  }

  [part='required-indicator']::after {
    content: var(--vaadin-input-field-required-indicator, var(--lumo-required-field-indicator, '\2022'));
    transition: opacity 0.2s;
    opacity: 0;
    color: var(
      --vaadin-input-field-required-indicator-color,
      var(--lumo-required-field-indicator-color, var(--lumo-primary-text-color))
    );
    position: relative;
    width: 1em;
    text-align: center;
  }

  :host([required]) [part='required-indicator']::after {
    opacity: 1;
  }

  :host([invalid]) [part='required-indicator']::after {
    color: var(
      --vaadin-input-field-required-indicator-color,
      var(--lumo-required-field-indicator-color, var(--lumo-error-text-color))
    );
  }
}