body{font-size: 1.14vmax;font-family: sans-serif;margin: 0;}

.outer-div
{
     display: table;
     position: absolute;
     height: 100%;
     width: 100%;
     background: radial-gradient(white,#e8e8e8);
}
.mid-div
{
     display: table-cell;
     vertical-align: middle;
}
.center-div
{
     margin: 0 auto;
     max-width: 50vmax;
     padding-bottom: 10%;
}