Well uh mm oddly the CSS works with the editor but does not work after publication
I allow myself to suggest a small correction, and at home it works.
(Test with chrome/windows10 & Android)
result with your css
result after the small correction
the correction
<pre><span><style>
[data-test="app-hr"] {
background-color: rgb(246, 246, 246);
padding:0px;
}
[data-test="app-hr"] .sep-line {
background-color: rgb(246, 246, 246);
}
[data-test="app-hr"]:after {
content: "";
position:relative;
top:-30px;
height:20px;
border-bottom-right-radius: 15px;
border-bottom-left-radius: 15px;
background:#fff;
box-shadow: 0 3px 0 0 rgb(226, 226, 226);
z-index:0 !important;
}
[data-test="app-hr"]:before {
content: "";
position:relative;
top:30px;
height:20px;
border-top-right-radius: 15px;
border-top-left-radius: 15px;
background:#fff;
box-shadow: 0 -15px 0 0 rgb(246, 246, 246);
z-index:0 !important;
}
</style></span></pre>