Answers for "alighn flex right side item in bottom in row direction flexbox"

flex force div right side

.parent {
  display: flex;
}
.child {
  margin-left: auto;
  order: 2;
}

align items left after flex-direction row reverse

#main {
  width: 400px;
  height: 400px;
  border: 1px solid #c3c3c3;
  display: flex;
  flex-direction: row-reverse;
  align-items: flex-start;
  justify-content: flex-end; <------need this
}

#main div {
  width: 50px;
  height: 50px;
}