SCSS in Tanstack, Hydration Issue & FOUC

is there a recommended way to use SCSS files in tanstack?

if I import the SCSS file barebones like

import "../styles.scss"

import "../styles.scss"

import "../styles.scss"

import "../styles.scss", I see FOUC (flash of unstyled content), but if I link it as a stylesheet by using

import appCss from "../styles.scss"

import appCss from "../styles.scss"

import appCss from "../styles.scss"

import appCss from "../styles.scss" I get hydration errors.