Disclosure
Use the details and summary elements to create expand-and-collapse disclosure components.
Put your entire content inside a details element. The heading that should act as the toggle goes inside a summary element. Use the open attribute to make your disclosure component expanded by default.
<details>
<summary>The toggle</summary>
The content.
</details>
<details open>
<summary>Another toggle</summary>
Expanded by default
</details>
You can style the dropdown arrow with CSS.
/**
* 1. Styling for Firefox and other non-webkit/blink browsers
* 2. Styling for webkit and blink
*/
summary, /* 1 */
summary::-webkit-details-marker { /* 2 */
list-style-image: url('');
}