If you're finding some fonts are rendering thicker/heavier in the Webflow preview and browser vs your design in Figma/Sketch etc, just add this CSS to the custom code section inside head tags:
<style>
body {-webkit-font-smoothing: antialiased;
-moz-font-smoothing: antialiased;
-o-font-smoothing: antialiased;}
</style>
FYI: You'll see the changes in the published site rather than the preview