How to pass owncloud through nginx with subdomain added?

Question

Nginx

Good afternoon! On one server, nginx is running (not configured by me, the tuner cannot be found), a domain with subdomains scattered over other servers looks at it. I decided to raise owncloud on one free machine, with a subdomain and hiding /owncloud/. I am zero in nginx. Here is the configuration:

server {
    listen                  80;
    listen                  443 ssl;
    server_name             cloud.домен.ru;

    rewrite ^(/owncloud/.*)$ https://$server_name$request_uri? permanent;

    ssl_certificate         домен.ru_bundle.crt;
    ssl_certificate_key     домен.ru.key;
    ssl_protocols           TLSv1 TLSv1.1 TLSv1.2;
    ssl_ciphers             HIGH:!aNULL:!MD5;
 
    server_name_in_redirect on;
    keepalive_timeout       70;
                                                        
#       access_log  logs/host.access.log  main;
             
        rewrite ^/(.*)$ /owncloud/$1 last;
                                
        location /owncloud/ {
                proxy_pass http://10.10.10.11:80;
                proxy_redirect http://cloud.домен.ru/owncloud /;

                proxy_set_header   Host             $host;
                proxy_set_header   X-Real-IP        $remote_addr;
                proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
                client_max_body_size       10m;
                client_body_buffer_size    128k;
                proxy_connect_timeout      90;
                proxy_send_timeout         90;
                proxy_read_timeout         90;
                                                                                                        
                proxy_buffer_size          4k;
                proxy_buffers              4 32k;
                proxy_busy_buffers_size    64k;
                proxy_temp_file_write_size 64k;
      }
}

Gives URL with double slash and not working css and js:
https://cloud.домен.ru//index.php/login
I repeat. It is far from Nginx, and this configuration is just an adaptation of one of the existing ones.
Thank you!