只要最后的斜线可选的：

Just make the trailing slash optional:

RewriteRule ^videos/login/?$ /videos/login.php

不过，你***只使用一个变体（带或不带斜线）和重定向一个到另一个：

But you should better use just one variant (with or without trailing slash) and redirect one to the other:

# add trailing slash
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule .*[^/]$ /$0/ [L,R=301]

# remove trailing slash
RewriteRule (.*)/$ /$1 [L,R=301]