htaccess subdirectory and wordpress - wordpress

Question

I have a php based site with wordpress installed in a subdirectory.
The main php site has urls in the following form
http://www.smokescreencreative.co.uk/nameofpage
which are rewritten using htaccess so they actually access pages like so:
http://www.smokescreencreative.co.uk/index.php?pid=$1
This all works as needed. My problem is with the /blog subdirectory. When in the blog part of the site trying to click on a link back to the main part of the site actually directs to
http://www.smokescreencreative.co.uk/blog/nameofpage
instead of
http://www.smokescreencreative.co.uk/nameofpage
as required and I am getting a 404 error because there is nothing there. I think this must be down to my htaccess files but I can't work out how to make it so the links to the main php page take the form I want but the blog post etc stay in the /blog/nameofpage format.
I did manage to get it so /blog/nameofpage was bringing in the correct written content for the root pages but there was no styling or images and the url was still /blog/nameofpage and I would like it to be just /nameofpage if possible.
I've posted the htaccess code for the root directory and blog subdirectories below. any help with this would be much appreciated.
Thanks in advance
main root htaccess code: (works for the links in the root part of the site)
AddType application/x-httpd-php .php .html .htm
Options +FollowSymLinks
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.+)$ /index.php?pid=$1 [L]
htaccess code for the wordpress subdirectory
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /blog/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /blog/index.php [L]
</IfModule>
# END WordPress