hide/show message in one click

CLICK BUTTON TO KNOW WHY I USED IT

i have learned this code and i knew that this code will help me to hide or show messae in one click for my website or blogger
<details>
<summary>what i am learning?</summary>
<p>i can hide long message</p>
<p>it will make me easy to provide page like f.a.q</p>
<p>this is called details tag</p>
</details>

<details open="open">
<summary>why use open</summary>
<p>to make it defoult showing all pages</p>
<p>when page loads it will not hide message</p>
</details>

what i am learning?

i can hide long message
it will make me easy to provide page like f.a.q
this is called details tag
i will end this with summary

why use open

to make it defoult showing all pages
when page loads it will not hide message