@vaadin/vaadin-lumo-styles/src/components/accordion-panel.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_accordion-panel {
  :host {
    display: block;
    margin: 0;
    border-bottom: solid 1px var(--lumo-contrast-10pct);
  }

  :host([hidden]) {
    display: none !important;
  }

  [part='content'] {
    display: none;
    overflow: hidden;
  }

  :host([opened]) [part='content'] {
    display: block;
    overflow: visible;
  }

  :host(:last-child) {
    border-bottom: none;
  }

  :host([theme~='filled']) {
    border-bottom: none;
  }

  :host([theme~='filled']:not(:last-child)) {
    margin-bottom: 2px;
  }
}