Answers for "align div content in center"

css center image

.center {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

align div content center

.child {
  ...
  margin: 0 auto;
}

how to align contents of div in center

1. Enclose the div that you want to center with a parent element 
(commonly known as a wrapper or container)

2. Set “text-align: center” to parent element.

3. Then set the inside div to “display: inline-block”

div center

#inner {
  display: table;
  margin: 0 auto;
  border: 1px solid black;
}

#outer {
  border: 1px solid red;
  width:100%
}