Please try this.
Copy and paste the CSS below into rich text.
Good luck to you.
★Don’t forget to set the action for rich text.
<div class="box"></div>
<div class="text">
<div class="title">
Scroll by concatenating text and buttons.
</div>
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
<div class="button_a">
button_a</div></div>
<pre><span><style>
.box,.text{
top: 8rem;
}
.box{
position: fixed;
width: 90%;
height:400px; /*◀Outer box height*/
background-color: #e5f8fb;
border-radius: 10px;
box-shadow: rgb(0 0 0 / 100%) 0px 4px 10px;
}
.text{
position: fixed;
overflow-y: scroll;
width: 80%;
margin-left:5%;
height:360px; /*◀Inner text height*/
margin-top:5%;
font-size: 0.9rem;
line-height:1.2rem;
text-align: left;
}
.title{
font-size: 1.3rem;
line-height:1.5rem;
font-weight:bold;
margin-bottom:0.5rem;
}
.button_a {
margin-top: 1rem;
width: 60% ;
margin-left: 20%;
font-size: 1rem;
text-align: center;
border-radius: 0.7rem;
font-weight: bold;
background: #000;
padding: 4% 2% 4% 4%;
color: #fff !important;
}
