# Disable directory browsing
Options -Indexes

# Force all requests to index.html in this folder
DirectoryIndex index.html

# Redirect any access to files in this folder (except index.html) back to index.html
RewriteEngine On

# If the requested file or folder exists, serve it; otherwise, go to index.html
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^.*$ /folder/index.html [L]
