nginx config with spa and subdirectory root

I always seem to have problems with nginx configurations. My SPA is located at /mnt/q/app (pushstate is enabled) and the frontend root is located at client/public. Everything should be mapped to index.html, where the app picks up the route and decides what to do.

Full path to the index is /mnt/q/app/client/public/index.html.

I think I ran out of options by now. No matter what I do, I just get a 404 back from nginx, I think the configuration is simple enought and have no clue what's wrong.

server {
    listen 80;
    server_name app.dev;

    root /mnt/q/app;

    location / {
      root /client/public;
      try_files $uri @rewrites =404;
    }

    location @rewrites {
       rewrite ^(.+)$ /index.html last;
    }
}

Any help is appreciated.