Make content boxes have a 'read more' popout box for more than 4 lines. Recreating the 'testimonies' page from Teach Us Consent.

Hi there! 

I am trying to re-create a page format from another website without success.

Here is the website's page i am trying to recreate: https://www.teachusconsent.com/testimonies

Below is the content boxes with the Title, description text and 'read more' button: 

When clicking 'read more', a pop out box appears with the full description text:

I want to know how to create those boxes that have that have 4 lines max, a 'read more' button that makes a pop out box for the user to read the whole text (if it's more than 4 lines). 

Right now, no matter what content block I use on SS, this happens:

*The block with the most content in the description will set the size for all boxes. It makes the size look messy especially with long text in the description boxes. 

If you need anymore info, please let me know. 

Thanks in advance! 

create those boxes that have that have 4 lines max >> We can use CSS code to do this

but to create lightbox, you will need to use a 3rd party plugin

you can consider accordion feature, I meant click on Read more >> Show more text under, not lightbox

What do you think?