How to keep the first accordion tab open by default?

Store Design
1

The accordion works great and it’s the only one that works for me after having tried so many, maybe its the theme. But I need to have the first tab open by default. Here’s the code:

{% comment %}

{% endcomment %}

  {% assign description_parts = product.description | split: '### ' %}
  {% for part in description_parts %}
      {% unless part == blank %}
      {% assign part_parts = part | split: '' %}
      {% assign heading_handle = part_parts.first | handle %}
      ##### {{ part_parts.first }} +
      

{{ part_parts.last | remove: '

' | replace: '

','

' }}

    {% endunless %}
  {% endfor %}

Thanks in advance!

2

add this css code between and
#free-shipping is the first item.
If you want a better accordion.
message for me or mail for me.

#free-shipping {
display: block;
}