2 questions on html/css?

Question

css

1. jsfiddle.net/mhof8rkL
Why does a paragraph indent (similarly for blocks) appear relative to the window, and not the block in which it is located?
2. There is a horizontal menu:

Three dots between items, how to implement?

Answer 1

1) Google "indentation collapse". It is treated by adding a border or padding to the parent block on top.
2) boder-left: dotted, set the desired line height and remove from the first element (fist-child)