The rule is the same as with any other use of the... 'All' makes no difference
If you are talking about a specific group, you would use the:
Pass me all the apples in the bowl
If you are talking about apples as a 'thing' but not as individual apples, you would not use the:
All apples are delicious
To translate this to your case, if you are talking about the elements on one page you would use the:
Some of the elements on the page are left aligned, the rest are justified. It looks strange.
If you are talking about elements in general you would not:
Note that in the latter case of both examples we are talking about apples/elements as a 'thing' or concept, whereas in the former we are talking about individual objects.