RewriteEngine On

# agar file/folder direct exist nahi karta tabhi rewrite karo
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d

# single slug ko blog.php pe forward karo
RewriteRule ^([a-zA-Z0-9-]+)/?$ blog.php?slug=$1 [L,QSA]