[css] div align

center

.center1 {
    margin: auto;
}
.center2 {
    margin-left: auto;
    margin-right: auto;
}

left, right

.left {
  position: absolute;
  left: 0px;
}
.right {
  position: absolute;
  right: 0px;
}

left, right 2

.left {
  float: left;
}
.right {
  float: right;
}