Answers for "center align a div in side parent"

keeping elements of container in center

.container {
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”