how to align card in center in css code example

Example 1: center card in bootstrap stack overflow

.card {
        margin: 0 auto; /* Added */
        float: none; /* Added */
        margin-bottom: 10px; /* Added */
}

Example 2: center content/card css

.container {
  display: flex;
  justify-content: center;
  flex-direction: row;
}