CSS Margin collapsing using margin: auto; - css

Question

I searched over Stackoverflow though many posts but I didn't found the solution.
I'm trying to align my text vertically, using margin: auto;
It seems there is a margin collapsing problem, if you wanna check this example:
// HTML
<div class="outer">
<div class="inner">Hello</div>
</div>
<div class="outer2">
<div class="inner">Trying to center this text vertically</div>
</div>
// CSS
.inner {
margin: auto 0;
height: 20px;
color: white;
}
.outer {
background-color: red;
}
.outer2 {
background-color: blue;
height: 200px;
}
If you want to play on my code, click here

Answer 1

I don't believe there's a good way to vertically align content using margin: auto 0 like you've set it up. To get the inner divs vertically centered, here's a simple way by modifying .inner:
.inner {
height: 200px;
color: white;
line-height: 200px;
}

Answer 2

The display does the magic. Display: table-cell on inner and display: table on outer div. And finally on inner div you put vertical-align: middle or whatever position that you want.
.inner {
display: table-cell;
vertical-align: middle;
height: 20px;
color: white;
}
.outer2 {
text-align: center;
background-color: blue;
height: 200px;
display: table;
width: 100%;
}

Answer 3

I would advise you to use flexbox
add this to outer2 class
.outer2 {
background-color: blue;
height: 200px;
display:flex;
align-items:center;
}
And for horizontal align you can use justify-content:center
align-item:center will align items in center of div vertically ,

Answer 4

.outer2 {
display: flex;
justify-content: center, left;
background-color: blue;
height: 200px;
}

Answer 5

you are trying to align the entire inner div by giving margin:auto. You can use text-align: center if you want to align the text. If you need to align the entire div then mention height and width for inner div. I have posted fiddle link please check
http://jsfiddle.net/ajaycoder/n1rz0bts/4/
.inner {
margin: auto ;
color: white;
width:50%;
border: solid 1px red;
height:50%;
}