Some questions about BEM?

Question

css

Hello. I'm studying bam and I have some questions

1. How to position blocks? If I need a block that is, for example, in the center, can I write in the styles of this block margin: 0 auto;?
   
2. As I saw modifiers should look like this element_key_value is it possible to create modifiers without being tied to an element, for example color_red?
   
3. I saw classes such as page, content-wrapper, and maybe there is where to read about them in Russian?
   

Answer 1

frontender.info/MindBEMding
https://nicothin.github.io/idiomatic-pre-CSS/

Answer 2

Not a BEM expert, but
1. Blocks also have a parent. Therefore, the block is also an "element" of some block. It will be: "some-block header__block" where you hang all the design on "some-block", and positioning on "header__block"
2. No. It's written in the docs. The modifier does not exist separately. You can create a "mixin" ... like a universal class, with a set of rules.
3. The question is not understood

Answer 3

1. You can, for example, in the parent block, mix an element to the centered block

{
    block: 'parent',
    content: {
        block: 'child',
        mix: {  block: 'parent', elem: 'childy'  }
    }
}

and then
2. The modifier can only be used in relation to something (block or element)
3. Please specify the question