Answers for "how to make a container items horizontally cenyer"

css center image

.center {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

vertical align css

/*
For a flexed item you can you align - items to center content vertically
you can use justify content to center horizontally
*/

.container {
  display: flex;
  align-items: center;
  justify-content: center;
}