gitbook/packages/react-math/css/default.css

/** Hide the KaTeX HTML output, while it's loading */
body:not(.katex-loaded) .katex-html {
    display: none;
}

/** Align the MathJax output with the font-size used by KaTeX */
mjx-container[jax='CHTML'] {
    font-size: 1.21em;
}