SCSS does not run, SCSS/SASS is converted to CSS, and yes, writing a media query within SCSS will be converted to CSS correctly, the SCSS language is not a usage language ("executable") and yes to facilitate code development and repetitions and in the end it is converted to CSS, something like:
ul#menu
{
li {
text-align: left;
@media screen and (max-width: 500px)
{
text-align: center;
}
}
}
Is converted into:
ul#menu li {
text-align: left;
}
@media screen and (max-width: 500px) {
ul#menu li {
text-align: center;
}
}
Even in the official DOC itself has examples: https://sass-lang.com/documentation/file.SAS_REFERENCE.html#media
If you have doubts that something will or will not work you can install SCSS outside of React (React as well as Ionic already have with the SCSS compiler internally) or use an online tool: