Nested classes selectors

Answer 1

You can use

span.welcome
#top .welcome
#top div.txt span.welcome
.welcome

Answer 2

If you want to use that 'welcome' class for perticular span tag than you can use two ways like...

.txt span.welcome

or

span.welcome

it will works for your CSS class in your code perfectly.

this is the concept of nesting class you can directly refer from internet sources too.

Answer 3

.welcome

#top div.txt .welcome

div#top div.txt span.welcome

it depends on how specific you want to be

Answer 4

div#top div.txt span.welcome

or

#top div.txt .welcome

or some other variation thereof...

Answer 5

#top .txt .welcome{}

Answer 6

#top .txt is not #top.txt the latter means that the matched element has the id AND the class, while the former means that the matched element has the class, and one of its ancestors element has the id