Posição absoluta Div Center
.child {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}
Grieving Gemsbok
.child {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}position: absolute;
margin-left: auto;
margin-right: auto;
left: 0;
right: 0;#content {
position: absolute;
left: 0;
right: 0;
margin-left: auto;
margin-right: auto;
width: 100px; /* Need a specific value to work */
}position: absolute;
margin-left: auto;
margin-right: auto;
left: 0;
right: 0;
text-align: center;
.container {
left:0;
right:0;
margin-left: auto;
margin-right: auto;
position: absolute;
width: 40%;
outline: 1px solid black;
background: white;
}