RewriteEngine on
RewriteBase /

# do not do anything for already existing files
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule .+ - [L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
# if static asset do not do anything
RewriteRule (.*)(css|js|html|png|jpg|jpeg|gif|bmp|ico|json|csv|otf|eot|svg|svgz|ttf|woff|woff2|ijmap|pdf|tif|map)$ - [L,R=404]
RewriteRule (.*) /index.html [L]