È stata la prima cosa che ho fatto, ma non va.
Allora, ho inserito[/size]table#zktm { margin: auto !important;}core/assets/css/layout.css ma non va.
In CSS non c'è un file template.css, ma solo seguenti:
/public_html/templates/avatar_simple/core/assets/css/admin.css
/public_html/templates/avatar_simple/core/assets/css/core_joomla.css
/public_html/templates/avatar_simple/core/assets/css/index.html
/public_html/templates/avatar_simple/core/assets/css/layout.css
/public_html/templates/avatar_simple/core/assets/css/reset.css
/public_html/templates/avatar_simple/core/assets/css/reset_rtl.css
/public_html/templates/avatar_simple/core/assets/css/responsive.css
/public_html/templates/avatar_simple/core/assets/css/text.css
/public_html/templates/avatar_simple/core/assets/css/text_rtl.css[/size][/font]