Apache htaccess到NGINX

I'm trying to understand how NGINX url rewrite is different from Apaches url rewrite, So here what i've tried

Fomr my .htaccess file

RewriteEngine on
RewriteRule ^(index|login|logout|404)/?$ $1.php [NC,L]
RewriteRule ^/(post|topic)/([^/]+)/?$ post.php?post=$1&title=$2 [L,QSA]

i didn't understand how to convert them to NGINX so as i little understood was turning the rules to the following

location / { 
    rewrite ^/(index|login|logout|404)/?$ /$1.php last;
    rewrite ^/(post|topic)/([^/]+)/?$ /post.php?post=$1&title=$2 last; 
}

i went to my NGINX.conf file and did added the new rules inside server {} but nothing worked, then inside of it tried to add it inside location / {} which already exists, and didn't work either.

My NGINX.conf file is like this

# Begin HTTP Server
server {
    listen 80; # IPv4
    server_name localhost;

    ## Parametrization using hostname of access and log filenames.
    access_log logs/localhost_access.log;
    error_log logs/localhost_error.log;

    ## Root and index files.
    root html;
    index  index.php index.html index.htm;

    ## If no favicon exists return a 204 (no content error).
    location = /favicon.ico {
        try_files $uri =204;
        log_not_found off;
        access_log off;
    }

    ## Don't log robots.txt requests.
    location = /robots.txt {
        allow all;
        log_not_found off;
        access_log off;
    }
    ## Try the requested URI as files before handling it to PHP.
    location / {
        ## Regular PHP processing.
        location ~ \.php$ {
            try_files  $uri =404;
            fastcgi_pass   php_processes;
            fastcgi_index  index.php;
            fastcgi_param  SCRIPT_FILENAME    $document_root$fastcgi_script_name;
            include        fastcgi_params;
        }

        ## Static files
        location ~* \.(?:css|gif|htc|ico|js|jpe?g|png|swf)$ {
            expires max;
            log_not_found off;
            ## No need to bleed constant updates. Send the all shebang in one
            ## fell swoop.
            tcp_nodelay off;
            ## Set the OS file cache.
            open_file_cache max=1000 inactive=120s;
            open_file_cache_valid 45s;
            open_file_cache_min_uses 2;
            open_file_cache_errors off;
        }

        ## Keep a tab on the 'big' static files.
        location ~* ^.+\.(?:ogg|pdf|pptx?)$ {
            expires 30d;
            ## No need to bleed constant updates. Send the all shebang in one
            ## fell swoop.
            tcp_nodelay off;
        }
        } # / location

} 
# End HTTP Server

# Begin HTTPS Server
server {
    listen 443 http2 ssl;
    server_name localhost;
    ssl_certificate      cert.pem;
    ssl_certificate_key  key.pem;
    ssl_session_cache   shared:SSL:10m;
    ssl_session_timeout 10m;

    ## Parametrization using hostname of access and log filenames.
    access_log logs/localhost_access.log;
    error_log logs/localhost_error.log;

    ## Root and index files.
    root html;
    index  index.php index.html index.htm;

    ## If no favicon exists return a 204 (no content error).
    location = /favicon.ico {
        try_files $uri =204;
        log_not_found off;
        access_log off;
    }

    ## Don't log robots.txt requests.
    location = /robots.txt {
        allow all;
        log_not_found off;
        access_log off;
    }
    ## Try the requested URI as files before handling it to PHP.
    location / {

        ## Regular PHP processing.
        location ~ \.php$ {
            try_files  $uri =404;
            fastcgi_pass   php_processes;
            fastcgi_index  index.php;
            fastcgi_param  SCRIPT_FILENAME    $document_root$fastcgi_script_name;
            include        fastcgi_params;
        }

        ## Static files are served directly.
        location ~* \.(?:css|gif|htc|ico|js|jpe?g|png|swf)$ {
            expires max;
            log_not_found off;
            ## No need to bleed constant updates. Send the all shebang in one
            ## fell swoop.
            tcp_nodelay off;
            ## Set the OS file cache.
            open_file_cache max=1000 inactive=120s;
            open_file_cache_valid 45s;
            open_file_cache_min_uses 2;
            open_file_cache_errors off;
        }

        ## Keep a tab on the 'big' static files.
        location ~* ^.+\.(?:ogg|pdf|pptx?)$ {
            expires 30d;
            ## No need to bleed constant updates. Send the all shebang in one
            ## fell swoop.
            tcp_nodelay off;
        }
        } # / location
} # End HTTPS Server

Do i have to add the rules twice fro each HTTP AND HTTPS server? And If possible i need an explaination with example built on my rules to understand it correctly, Also i noticed try_files $uri =404; so i wonder if it is the 404 rewrite rule or not.