Adjectives does not have its own gender – they have the same gender as noun has.
Adjectives also doesn't have its own number – they have the same gender as noun has.
Adjectives are declined – they have the same case as noun has. However, adjectives doesn't have “sub-cases”, they only decline in “basic” and “additional” cases; instead of “sub-cases” they use “basic” cases, even if the noun is declined in “sub-case”.
When the noun is declined in “sub-case” the adjective is declined in the “basic” case which is superior to the “sub-case” in which the noun is; and the adjective is placed AFTER the noun and not before it as normally. Nevertheless, both noun and the adjective can be declined in the corresponding “basic” case; here the adjective is placed BEFORE the noun, as normally.
Adjectives have a special characteristic named “correspondence”, which has the adjectives in accusative for both genders and all three numbers.
Adjectives deriving from noun which are written with capital letter, are also written with capital letter. Articles aren't necessary any more, unless the noun is a name (of a country, etc.).