How to style <details> and <summary>? - css

Question

Just found out about and tags. Default gives out a very crude style. I had success using the ::marker Pseudo Element to remove the default marker, but don't know how to put it on the right side. Used the ::after Pseudo Element but can't animate it (Rotate 180deg or scale it) when the summary "opens". Is there a proper way to do it? Or did I miss anything with my method? Thanks.
PS: Since I am a newb, I don't know how to get the Google icon font to the codepen. However, you will see what I tried to do with the expand_arrow icon.
* {
box-sizing: border-box;
margin: 0px;
padding: 0px;
}
.thing {
background-color: cadetblue;
width: 100%;
height: 100vh;
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
}
.new_game {
font-size: 3rem;
}
.what_is_question {
background-color: cornflowerblue;
cursor: pointer;
}
.what_is_question[open] {
background-color: darkmagenta;
}
.what_is_question {
font-size: 5rem;
}
.question_title {
position: relative;
}
.question_title::after {
content: url(./images/expand_more_black_24dp.svg);
}
.what_is_question[open] .question_title::after {
transform: rotate(180deg);
}
.question_title::marker {
content: none;
}
.answer {
background-color: darkkhaki;
font-size: 3rem;
padding-left: 3.5%;
}
<div class="thing">
<h1 class="new_game">QnA</h1>
<details class="what_is_question">
<summary class="question_title">What is the question?</summary>
<p class="answer">The question is the answer.</p>
</details>
</div>
https://codepen.io/consig1iere/pen/bGWXRMW

Answer 1

The problem is that you can't apply transforms to elements with display: inline.
So add display: inline-block; to your .question-title
.what_is_question[open] .question_title::after {
display: inline-block;
transform: rotate(180deg);
}